diff --git a/arangod/HashIndex/hash-array.c b/arangod/HashIndex/hash-array.c
index 0dae118c9e..b57dbe41f1 100644
--- a/arangod/HashIndex/hash-array.c
+++ b/arangod/HashIndex/hash-array.c
@@ -239,7 +239,7 @@ static void AddNewElement (TRI_hash_array_t* array,
   i = hash % array->_nrAlloc;
 
   while (! IsEmptyElement(array, &array->_table[i])) {
-    i = (i + 1) % array->_nrAlloc;
+    i = TRI_IncModU64(i, array->_nrAlloc);
   }
 
   // ...........................................................................
@@ -441,7 +441,7 @@ TRI_hash_index_element_t* TRI_LookupByKeyHashArray (TRI_hash_array_t* array,
 
   while (! IsEmptyElement(array, &array->_table[i])
       && ! IsEqualKeyElement(array, key, &array->_table[i])) {
-    i = (i + 1) % array->_nrAlloc;
+    i = TRI_IncModU64(i, array->_nrAlloc);
   }
 
   // ...........................................................................
@@ -490,7 +490,7 @@ TRI_hash_index_element_t* TRI_LookupByElementHashArray (TRI_hash_array_t* array,
 
   while (! IsEmptyElement(array, &array->_table[i])
       && ! IsEqualElementElement(array, element, &array->_table[i])) {
-    i = (i + 1) % array->_nrAlloc;
+    i = TRI_IncModU64(i, array->_nrAlloc);
   }
 
   // ...........................................................................
@@ -545,7 +545,7 @@ int TRI_InsertElementHashArray (TRI_hash_array_t* array,
 
   while (! IsEmptyElement(array, &array->_table[i])
       && ! IsEqualElementElement(array, element, &array->_table[i])) {
-    i = (i + 1) % array->_nrAlloc;
+    i = TRI_IncModU64(i, array->_nrAlloc);
   }
 
   arrayElement = &array->_table[i];
@@ -623,7 +623,7 @@ int TRI_InsertKeyHashArray (TRI_hash_array_t* array,
 
   while (! IsEmptyElement(array, &array->_table[i])
       && ! IsEqualKeyElement(array, key, &array->_table[i])) {
-    i = (i + 1) % array->_nrAlloc;
+    i = TRI_IncModU64(i, array->_nrAlloc);
   }
 
   arrayElement = &array->_table[i];
@@ -696,7 +696,7 @@ int TRI_RemoveElementHashArray (TRI_hash_array_t* array,
 
   while (! IsEmptyElement(array, &array->_table[i])
       && ! IsEqualElementElement(array, element, &array->_table[i])) {
-    i = (i + 1) % array->_nrAlloc;
+    i = TRI_IncModU64(i, array->_nrAlloc);
   }
 
   arrayElement = &array->_table[i];
@@ -723,7 +723,7 @@ int TRI_RemoveElementHashArray (TRI_hash_array_t* array,
   // so that there are no gaps in the array
   // ...........................................................................
 
-  k = (i + 1) % array->_nrAlloc;
+  k = TRI_IncModU64(i, array->_nrAlloc);
 
   while (! IsEmptyElement(array, &array->_table[k])) {
     uint64_t j = HashElement(array, &array->_table[k]) % array->_nrAlloc;
@@ -734,7 +734,7 @@ int TRI_RemoveElementHashArray (TRI_hash_array_t* array,
       i = k;
     }
 
-    k = (k + 1) % array->_nrAlloc;
+    k = TRI_IncModU64(k, array->_nrAlloc);
   }
 
   return TRI_ERROR_NO_ERROR;
@@ -765,7 +765,7 @@ int TRI_RemoveKeyHashArray (TRI_hash_array_t* array,
 
   while (! IsEmptyElement(array, &array->_table[i])
       && ! IsEqualKeyElement(array, key, &array->_table[i])) {
-    i = (i + 1) % array->_nrAlloc;
+    i = TRI_IncModU64(i, array->_nrAlloc);
   }
 
   arrayElement = &array->_table[i];
@@ -791,7 +791,7 @@ int TRI_RemoveKeyHashArray (TRI_hash_array_t* array,
   // and now check the following places for items to move here
   // ...........................................................................
 
-  k = (i + 1) % array->_nrAlloc;
+  k = TRI_IncModU64(i, array->_nrAlloc);
 
   while (! IsEmptyElement(array, &array->_table[k])) {
     uint64_t j = HashElement(array, &array->_table[k]) % array->_nrAlloc;
@@ -802,7 +802,7 @@ int TRI_RemoveKeyHashArray (TRI_hash_array_t* array,
       i = k;
     }
 
-    k = (k + 1) % array->_nrAlloc;
+    k = TRI_IncModU64(k, array->_nrAlloc);
   }
 
   // ...........................................................................
@@ -861,7 +861,7 @@ TRI_vector_pointer_t TRI_LookupByKeyHashArrayMulti (TRI_hash_array_t* array,
       TRI_PushBackVectorPointer(&result, &array->_table[i]);
     }
 
-    i = (i + 1) % array->_nrAlloc;
+    i = TRI_IncModU64(i, array->_nrAlloc);
   }
 
   // ...........................................................................
@@ -904,7 +904,7 @@ TRI_vector_pointer_t TRI_LookupByElementHashArrayMulti (TRI_hash_array_t* array,
       TRI_PushBackVectorPointer(&result, &array->_table[i]);
     }
 
-    i = (i + 1) % array->_nrAlloc;
+    i = TRI_IncModU64(i, array->_nrAlloc);
   }
 
   // ...........................................................................
@@ -944,7 +944,7 @@ int TRI_InsertElementHashArrayMulti (TRI_hash_array_t* array,
 
   while (! IsEmptyElement(array, &array->_table[i])
       && ! IsEqualElementElement(array, element, &array->_table[i])) {
-    i = (i + 1) % array->_nrAlloc;
+    i = TRI_IncModU64(i, array->_nrAlloc);
   }
 
   arrayElement = &array->_table[i];
@@ -1023,7 +1023,7 @@ int TRI_InsertKeyHashArrayMulti (TRI_hash_array_t* array,
   // ...........................................................................
 
   while (! IsEmptyElement(array, &array->_table[i])) {
-    i = (i + 1) % array->_nrAlloc;
+    i = TRI_IncModU64(i, array->_nrAlloc);
   }
 
   arrayElement = &array->_table[i];
@@ -1082,7 +1082,7 @@ int TRI_RemoveElementHashArrayMulti (TRI_hash_array_t* array,
 
   while (! IsEmptyElement(array, &array->_table[i])
       && ! IsEqualElementElement(array, element, &array->_table[i])) {
-    i = (i + 1) % array->_nrAlloc;
+    i = TRI_IncModU64(i, array->_nrAlloc);
   }
 
   arrayElement = &array->_table[i];
@@ -1108,7 +1108,7 @@ int TRI_RemoveElementHashArrayMulti (TRI_hash_array_t* array,
   // and now check the following places for items to move here
   // ...........................................................................
 
-  k = (i + 1) % array->_nrAlloc;
+  k = TRI_IncModU64(i, array->_nrAlloc);
 
   while (! IsEmptyElement(array, &array->_table[k])) {
     uint64_t j = HashElement(array, &array->_table[k]) % array->_nrAlloc;
@@ -1119,7 +1119,7 @@ int TRI_RemoveElementHashArrayMulti (TRI_hash_array_t* array,
       i = k;
     }
 
-    k = (k + 1) % array->_nrAlloc;
+    k = TRI_IncModU64(k, array->_nrAlloc);
   }
 
   return TRI_ERROR_NO_ERROR;
@@ -1150,7 +1150,7 @@ int TRI_RemoveKeyHashArrayMulti (TRI_hash_array_t* array,
 
   while (! IsEmptyElement(array, &array->_table[i])
       && ! IsEqualKeyElement(array, key, &array->_table[i])) {
-    i = (i + 1) % array->_nrAlloc;
+    i = TRI_IncModU64(i, array->_nrAlloc);
   }
 
   arrayElement = &array->_table[i];
@@ -1176,7 +1176,7 @@ int TRI_RemoveKeyHashArrayMulti (TRI_hash_array_t* array,
   // and now check the following places for items to move here
   // ...........................................................................
 
-  k = (i + 1) % array->_nrAlloc;
+  k = TRI_IncModU64(i, array->_nrAlloc);
 
   while (! IsEmptyElement(array, &array->_table[k])) {
     uint64_t j = HashElement(array, &array->_table[k]) % array->_nrAlloc;
@@ -1187,7 +1187,7 @@ int TRI_RemoveKeyHashArrayMulti (TRI_hash_array_t* array,
       i = k;
     }
 
-    k = (k + 1) % array->_nrAlloc;
+    k = TRI_IncModU64(k, array->_nrAlloc);
   }
 
   return TRI_ERROR_NO_ERROR;
diff --git a/arangod/VocBase/document-collection.c b/arangod/VocBase/document-collection.c
index adb8270e95..e0665a8fb1 100644
--- a/arangod/VocBase/document-collection.c
+++ b/arangod/VocBase/document-collection.c
@@ -3741,6 +3741,7 @@ static int FillIndex (TRI_document_collection_t* document,
   void** end;
   void** ptr;
   int res;
+  double starttime;
 
   primary = &document->base;
 
@@ -3754,6 +3755,9 @@ static int FillIndex (TRI_document_collection_t* document,
   }
 
 
+  starttime = TRI_microtime();
+  printf("FillIndex _iid=%llu start time: %f\n",(unsigned long long) idx->_iid,
+         starttime);
   inserted = 0;
 
   for (;  ptr < end;  ++ptr) {
@@ -3780,6 +3784,8 @@ static int FillIndex (TRI_document_collection_t* document,
       }
     }
   }
+  printf("FillIndex _iid=%llu time spent: %f\n",(unsigned long long) idx->_iid,
+         TRI_microtime()-starttime);
 
   return TRI_ERROR_NO_ERROR;
 }
diff --git a/lib/Basics/AssociativeArray.h b/lib/Basics/AssociativeArray.h
index 65fef8192b..5c735a5605 100644
--- a/lib/Basics/AssociativeArray.h
+++ b/lib/Basics/AssociativeArray.h
@@ -310,7 +310,7 @@ namespace triagens {
           uint64_t i = hash % _nrAlloc;
 
           while (!_desc.isEmptyElement(_table[i]) && !_desc.isEqualKeyElement(key, _table[i])) {
-            i = (i + 1) % _nrAlloc;
+            i = TRI_IncModU64(i, _nrAlloc);
 #ifdef TRI_INTERNAL_STATS
             _nrProbesF++;
 #endif
@@ -337,7 +337,7 @@ namespace triagens {
           uint64_t i = hash % _nrAlloc;
 
           while (!_desc.isEmptyElement(_table[i]) && !_desc.isEqualElementElement(element, _table[i])) {
-            i = (i + 1) % _nrAlloc;
+            i = TRI_IncModU64(i, _nrAlloc);
 #ifdef TRI_INTERNAL_STATS
             _nrProbesF++;
 #endif
@@ -363,7 +363,7 @@ namespace triagens {
           uint64_t i = hash % _nrAlloc;
 
           while (!_desc.isEmptyElement(_table[i]) && !_desc.isEqualElementElement(element, _table[i])) {
-            i = (i + 1) % _nrAlloc;
+            i = TRI_IncModU64(i, _nrAlloc);
 #ifdef TRI_INTERNAL_STATS
             _nrProbesA++;
 #endif
@@ -431,7 +431,7 @@ namespace triagens {
           uint64_t i = hash % _nrAlloc;
 
           while (!_desc.isEmptyElement(_table[i]) && !_desc.isEqualKeyElement(key, _table[i])) {
-            i = (i + 1) % _nrAlloc;
+            i = TRI_IncModU64(i, _nrAlloc);
 #ifdef TRI_INTERNAL_STATS
             _nrProbesA++;
 #endif
@@ -499,7 +499,7 @@ namespace triagens {
           uint64_t i = hash % _nrAlloc;
 
           while (!_desc.isEmptyElement(_table[i]) && !_desc.isEqualKeyElement(key, _table[i])) {
-            i = (i + 1) % _nrAlloc;
+            i = TRI_IncModU64(i, _nrAlloc);
 #ifdef TRI_INTERNAL_STATS
             _nrProbesD++;
 #endif
@@ -518,7 +518,7 @@ namespace triagens {
           _nrUsed--;
 
           // and now check the following places for items to move here
-          uint64_t k = (i + 1) % _nrAlloc;
+          uint64_t k = TRI_IncModU64(i, _nrAlloc);
 
           while (!_desc.isEmptyElement(_table[k])) {
             uint32_t j = _desc.hashElement(_table[k]) % _nrAlloc;
@@ -529,7 +529,7 @@ namespace triagens {
               i = k;
             }
 
-            k = (k + 1) % _nrAlloc;
+            k = TRI_IncModU64(k, _nrAlloc);
           }
 
           // return success
@@ -552,7 +552,7 @@ namespace triagens {
           uint64_t i = hash % _nrAlloc;
 
           while (!_desc.isEmptyElement(_table[i]) && !_desc.isEqualElementElement(element, _table[i])) {
-            i = (i + 1) % _nrAlloc;
+            i = TRI_IncModU64(i, _nrAlloc);
 #ifdef TRI_INTERNAL_STATS
             _nrProbesD++;
 #endif
@@ -568,7 +568,7 @@ namespace triagens {
           _nrUsed--;
 
           // and now check the following places for items to move here
-          uint64_t k = (i + 1) % _nrAlloc;
+          uint64_t k = TRI_IncModU64(i, _nrAlloc);
 
           while (!_desc.isEmptyElement(_table[k])) {
             uint32_t j = _desc.hashElement(_table[k]) % _nrAlloc;
@@ -579,7 +579,7 @@ namespace triagens {
               i = k;
             }
 
-            k = (k + 1) % _nrAlloc;
+            k = TRI_IncModU64(k, _nrAlloc);
           }
 
           // return success
@@ -639,7 +639,7 @@ namespace triagens {
           uint64_t i = hash % _nrAlloc;
 
           while (!_desc.isEmptyElement(_table[i])) {
-            i = (i + 1) % _nrAlloc;
+            i = TRI_IncModU64(i, _nrAlloc);
 #ifdef TRI_INTERNAL_STATS
             _nrProbesR++;
 #endif
diff --git a/lib/BasicsC/associative-multi.c b/lib/BasicsC/associative-multi.c
index 28576060ad..1c072ddeda 100644
--- a/lib/BasicsC/associative-multi.c
+++ b/lib/BasicsC/associative-multi.c
@@ -78,7 +78,7 @@ static void AddNewElement (TRI_multi_array_t* array, void* element) {
   i = hash % array->_nrAlloc;
 
   while (! array->isEmptyElement(array, array->_table + i * array->_elementSize)) {
-    i = (i + 1) % array->_nrAlloc;
+    i = TRI_IncModU64(i, array->_nrAlloc);
 #ifdef TRI_INTERNAL_STATS
     array->_nrProbesR++;
 #endif
@@ -252,7 +252,7 @@ TRI_vector_pointer_t TRI_LookupByKeyMultiArray (TRI_memory_zone_t* zone,
     }
 #endif
 
-    i = (i + 1) % array->_nrAlloc;
+    i = TRI_IncModU64(i, array->_nrAlloc);
   }
 
   // ...........................................................................
@@ -298,7 +298,7 @@ TRI_vector_pointer_t TRI_LookupByElementMultiArray (TRI_memory_zone_t* zone,
     }
 #endif
 
-    i = (i + 1) % array->_nrAlloc;
+    i = TRI_IncModU64(i, array->_nrAlloc);
   }
 
   // ...........................................................................
@@ -336,7 +336,7 @@ bool TRI_InsertElementMultiArray (TRI_multi_array_t* array, void* element, bool
   // search the table
   while (! array->isEmptyElement(array, array->_table + i * array->_elementSize)
          && ! array->isEqualElementElement(array, element, array->_table + i * array->_elementSize)) {
-    i = (i + 1) % array->_nrAlloc;
+    i = TRI_IncModU64(i, array->_nrAlloc);
 #ifdef TRI_INTERNAL_STATS
     array->_nrProbesA++;
 #endif
@@ -394,7 +394,7 @@ bool TRI_InsertKeyMultiArray (TRI_multi_array_t* array, void* key, void* element
 
   // search the table
   while (! array->isEmptyElement(array, array->_table + i * array->_elementSize)) {
-    i = (i + 1) % array->_nrAlloc;
+    i = TRI_IncModU64(i, array->_nrAlloc);
 #ifdef TRI_INTERNAL_STATS
     array->_nrProbesA++;
 #endif
@@ -438,7 +438,7 @@ bool TRI_RemoveElementMultiArray (TRI_multi_array_t* array, void* element, void*
   // search the table
   while (! array->isEmptyElement(array, array->_table + i * array->_elementSize)
          && ! array->isEqualElementElement(array, element, array->_table + i * array->_elementSize)) {
-    i = (i + 1) % array->_nrAlloc;
+    i = TRI_IncModU64(i, array->_nrAlloc);
 #ifdef TRI_INTERNAL_STATS
     array->_nrProbesD++;
 #endif
@@ -462,7 +462,7 @@ bool TRI_RemoveElementMultiArray (TRI_multi_array_t* array, void* element, void*
   array->_nrUsed--;
 
   // and now check the following places for items to move here
-  k = (i + 1) % array->_nrAlloc;
+  k = TRI_IncModU64(i, array->_nrAlloc);
 
   while (! array->isEmptyElement(array, array->_table + k * array->_elementSize)) {
     uint64_t j = array->hashElement(array, array->_table + k * array->_elementSize) % array->_nrAlloc;
@@ -473,7 +473,7 @@ bool TRI_RemoveElementMultiArray (TRI_multi_array_t* array, void* element, void*
       i = k;
     }
 
-    k = (k + 1) % array->_nrAlloc;
+    k = TRI_IncModU64(k, array->_nrAlloc);
   }
 
   return true;
@@ -500,7 +500,7 @@ bool TRI_RemoveKeyMultiArray (TRI_multi_array_t* array, void* key, void* old) {
   // search the table -- we can only match keys
   while (! array->isEmptyElement(array, array->_table + i * array->_elementSize)
          && ! array->isEqualKeyElement(array, key, array->_table + i * array->_elementSize)) {
-    i = (i + 1) % array->_nrAlloc;
+    i = TRI_IncModU64(i, array->_nrAlloc);
 #ifdef TRI_INTERNAL_STATS
     array->_nrProbesD++;
 #endif
@@ -524,7 +524,7 @@ bool TRI_RemoveKeyMultiArray (TRI_multi_array_t* array, void* key, void* old) {
   array->_nrUsed--;
 
   // and now check the following places for items to move here
-  k = (i + 1) % array->_nrAlloc;
+  k = TRI_IncModU64(i, array->_nrAlloc);
 
   while (! array->isEmptyElement(array, array->_table + k * array->_elementSize)) {
     uint64_t j = array->hashElement(array, array->_table + k * array->_elementSize) % array->_nrAlloc;
@@ -535,7 +535,7 @@ bool TRI_RemoveKeyMultiArray (TRI_multi_array_t* array, void* key, void* old) {
       i = k;
     }
 
-    k = (k + 1) % array->_nrAlloc;
+    k = TRI_IncModU64(k, array->_nrAlloc);
   }
 
   return true;
@@ -573,7 +573,7 @@ static void AddNewElementPointer (TRI_multi_pointer_t* array, void* element) {
   i = hash % array->_nrAlloc;
 
   while (array->_table[i] != NULL) {
-    i = (i + 1) % array->_nrAlloc;
+    i = TRI_IncModU64(i, array->_nrAlloc);
 #ifdef TRI_INTERNAL_STATS
     array->_nrProbesR++;
 #endif
@@ -744,7 +744,7 @@ TRI_vector_pointer_t TRI_LookupByKeyMultiPointer (TRI_memory_zone_t* zone,
       array->_nrProbesF++;
     }
 #endif
-    i = (i + 1) % array->_nrAlloc;
+    i = TRI_IncModU64(i, array->_nrAlloc);
   }
 
   // return whatever we found
@@ -770,7 +770,7 @@ void* TRI_LookupByElementMultiPointer (TRI_multi_pointer_t* array, void const* e
 
   // search the table
   while (array->_table[i] != NULL && ! array->isEqualElementElement(array, element, array->_table[i])) {
-    i = (i + 1) % array->_nrAlloc;
+    i = TRI_IncModU64(i, array->_nrAlloc);
 #ifdef TRI_INTERNAL_STATS
     array->_nrProbesF++;
 #endif
@@ -812,8 +812,10 @@ void* TRI_InsertElementMultiPointer (TRI_multi_pointer_t* array,
   // we use this flag to speed up initial insertion into the index, i.e. when the
   // index is built for a collection and we know for sure no duplicate elements
   // will be inserted
-  while (array->_table[i] != NULL && (! checkEquality || ! array->isEqualElementElement(array, element, array->_table[i]))) {
-    i = (i + 1) % array->_nrAlloc;
+  while (array->_table[i] != NULL && 
+         (! checkEquality || 
+          ! array->isEqualElementElement(array, element, array->_table[i]))) {
+    i = TRI_IncModU64(i, array->_nrAlloc);
 #ifdef TRI_INTERNAL_STATS
     array->_nrProbesA++;
 #endif
@@ -862,7 +864,7 @@ void* TRI_RemoveElementMultiPointer (TRI_multi_pointer_t* array, void const* ele
 
   // search the table
   while (array->_table[i] != NULL && ! array->isEqualElementElement(array, element, array->_table[i])) {
-    i = (i + 1) % array->_nrAlloc;
+    i = TRI_IncModU64(i, array->_nrAlloc);
 #ifdef TRI_INTERNAL_STATS
     array->_nrProbesD++;
 #endif
@@ -879,7 +881,7 @@ void* TRI_RemoveElementMultiPointer (TRI_multi_pointer_t* array, void const* ele
   array->_nrUsed--;
 
   // and now check the following places for items to move here
-  k = (i + 1) % array->_nrAlloc;
+  k = TRI_IncModU64(i, array->_nrAlloc);
 
   while (array->_table[k] != NULL) {
     uint64_t j = array->hashElement(array, array->_table[k]) % array->_nrAlloc;
@@ -890,7 +892,7 @@ void* TRI_RemoveElementMultiPointer (TRI_multi_pointer_t* array, void const* ele
       i = k;
     }
 
-    k = (k + 1) % array->_nrAlloc;
+    k = TRI_IncModU64(k, array->_nrAlloc);
   }
 
   // return success
diff --git a/lib/BasicsC/associative.c b/lib/BasicsC/associative.c
index 60e7f1ef15..e1bbbabffc 100644
--- a/lib/BasicsC/associative.c
+++ b/lib/BasicsC/associative.c
@@ -78,7 +78,7 @@ static void AddNewElement (TRI_associative_array_t* array, void* element) {
   i = hash % array->_nrAlloc;
 
   while (! array->isEmptyElement(array, array->_table + i * array->_elementSize)) {
-    i = (i + 1) % array->_nrAlloc;
+    i = TRI_IncModU64(i, array->_nrAlloc);
 #ifdef TRI_INTERNAL_STATS
     array->_nrProbesR++;
 #endif
@@ -244,7 +244,7 @@ void* TRI_LookupByKeyAssociativeArray (TRI_associative_array_t* array, void* key
   // search the table
   while (! array->isEmptyElement(array, array->_table + i * array->_elementSize)
          && ! array->isEqualKeyElement(array, key, array->_table + i * array->_elementSize)) {
-    i = (i + 1) % array->_nrAlloc;
+    i = TRI_IncModU64(i, array->_nrAlloc);
 #ifdef TRI_INTERNAL_STATS
     array->_nrProbesF++;
 #endif
@@ -292,7 +292,7 @@ void* TRI_LookupByElementAssociativeArray (TRI_associative_array_t* array, void*
   // search the table
   while (! array->isEmptyElement(array, array->_table + i * array->_elementSize)
          && ! array->isEqualElementElement(array, element, array->_table + i * array->_elementSize)) {
-    i = (i + 1) % array->_nrAlloc;
+    i = TRI_IncModU64(i, array->_nrAlloc);
 #ifdef TRI_INTERNAL_STATS
     array->_nrProbesF++;
 #endif
@@ -346,7 +346,7 @@ bool TRI_InsertElementAssociativeArray (TRI_associative_array_t* array, void* el
   // search the table
   while (! array->isEmptyElement(array, array->_table + i * array->_elementSize)
          && ! array->isEqualElementElement(array, element, array->_table + i * array->_elementSize)) {
-    i = (i + 1) % array->_nrAlloc;
+    i = TRI_IncModU64(i, array->_nrAlloc);
 #ifdef TRI_INTERNAL_STATS
     array->_nrProbesA++;
 #endif
@@ -399,7 +399,7 @@ bool TRI_InsertKeyAssociativeArray (TRI_associative_array_t* array, void* key, v
   // search the table
   while (! array->isEmptyElement(array, array->_table + i * array->_elementSize)
          && ! array->isEqualKeyElement(array, key, array->_table + i * array->_elementSize)) {
-    i = (i + 1) % array->_nrAlloc;
+    i = TRI_IncModU64(i, array->_nrAlloc);
 #ifdef TRI_INTERNAL_STATS
     array->_nrProbesA++;
 #endif
@@ -446,7 +446,7 @@ bool TRI_RemoveElementAssociativeArray (TRI_associative_array_t* array, void* el
   // search the table
   while (! array->isEmptyElement(array, array->_table + i * array->_elementSize)
          && ! array->isEqualElementElement(array, element, array->_table + i * array->_elementSize)) {
-    i = (i + 1) % array->_nrAlloc;
+    i = TRI_IncModU64(i, array->_nrAlloc);
 #ifdef TRI_INTERNAL_STATS
     array->_nrProbesD++;
 #endif
@@ -470,7 +470,7 @@ bool TRI_RemoveElementAssociativeArray (TRI_associative_array_t* array, void* el
   array->_nrUsed--;
 
   // and now check the following places for items to move here
-  k = (i + 1) % array->_nrAlloc;
+  k = TRI_IncModU64(i, array->_nrAlloc);
 
   while (! array->isEmptyElement(array, array->_table + k * array->_elementSize)) {
     uint64_t j = array->hashElement(array, array->_table + k * array->_elementSize) % array->_nrAlloc;
@@ -481,7 +481,7 @@ bool TRI_RemoveElementAssociativeArray (TRI_associative_array_t* array, void* el
       i = k;
     }
 
-    k = (k + 1) % array->_nrAlloc;
+    k = TRI_IncModU64(k, array->_nrAlloc);
   }
 
   // return success
@@ -508,7 +508,7 @@ bool TRI_RemoveKeyAssociativeArray (TRI_associative_array_t* array, void* key, v
   // search the table
   while (! array->isEmptyElement(array, array->_table + i * array->_elementSize)
          && ! array->isEqualKeyElement(array, key, array->_table + i * array->_elementSize)) {
-    i = (i + 1) % array->_nrAlloc;
+    i = TRI_IncModU64(i, array->_nrAlloc);
 #ifdef TRI_INTERNAL_STATS
     array->_nrProbesD++;
 #endif
@@ -532,7 +532,7 @@ bool TRI_RemoveKeyAssociativeArray (TRI_associative_array_t* array, void* key, v
   array->_nrUsed--;
 
   // and now check the following places for items to move here
-  k = (i + 1) % array->_nrAlloc;
+  k = TRI_IncModU64(i, array->_nrAlloc);
 
   while (! array->isEmptyElement(array, array->_table + k * array->_elementSize)) {
     uint64_t j = array->hashElement(array, array->_table + k * array->_elementSize) % array->_nrAlloc;
@@ -543,7 +543,7 @@ bool TRI_RemoveKeyAssociativeArray (TRI_associative_array_t* array, void* key, v
       i = k;
     }
 
-    k = (k + 1) % array->_nrAlloc;
+    k = TRI_IncModU64(k, array->_nrAlloc);
   }
 
   // return success
@@ -590,7 +590,7 @@ static void AddNewElementPointer (TRI_associative_pointer_t* array, void* elemen
   i = hash % array->_nrAlloc;
 
   while (array->_table[i] != NULL) {
-    i = (i + 1) % array->_nrAlloc;
+    i = TRI_IncModU64(i, array->_nrAlloc);
 #ifdef TRI_INTERNAL_STATS
     array->_nrProbesR++;
 #endif
@@ -796,7 +796,7 @@ void* TRI_LookupByKeyAssociativePointer (TRI_associative_pointer_t* array,
 
   // search the table
   while (array->_table[i] != NULL && ! array->isEqualKeyElement(array, key, array->_table[i])) {
-    i = (i + 1) % array->_nrAlloc;
+    i = TRI_IncModU64(i, array->_nrAlloc);
 #ifdef TRI_INTERNAL_STATS
     array->_nrProbesF++;
 #endif
@@ -826,7 +826,7 @@ void* TRI_LookupByElementAssociativePointer (TRI_associative_pointer_t* array,
 
   // search the table
   while (array->_table[i] != NULL && ! array->isEqualElementElement(array, element, array->_table[i])) {
-    i = (i + 1) % array->_nrAlloc;
+    i = TRI_IncModU64(i, array->_nrAlloc);
 #ifdef TRI_INTERNAL_STATS
     array->_nrProbesF++;
 #endif
@@ -864,7 +864,7 @@ void* TRI_InsertElementAssociativePointer (TRI_associative_pointer_t* array,
 
   // search the table
   while (array->_table[i] != NULL && ! array->isEqualElementElement(array, element, array->_table[i])) {
-    i = (i + 1) % array->_nrAlloc;
+    i = TRI_IncModU64(i, array->_nrAlloc);
 #ifdef TRI_INTERNAL_STATS
     array->_nrProbesA++;
 #endif
@@ -922,7 +922,7 @@ void* TRI_InsertKeyAssociativePointer (TRI_associative_pointer_t* array,
 
   // search the table
   while (array->_table[i] != NULL && ! array->isEqualKeyElement(array, key, array->_table[i])) {
-    i = (i + 1) % array->_nrAlloc;
+    i = TRI_IncModU64(i, array->_nrAlloc);
 #ifdef TRI_INTERNAL_STATS
     array->_nrProbesA++;
 #endif
@@ -984,7 +984,7 @@ int TRI_InsertKeyAssociativePointer2 (TRI_associative_pointer_t* array,
 
   // search the table
   while (array->_table[i] != NULL && ! array->isEqualKeyElement(array, key, array->_table[i])) {
-    i = (i + 1) % array->_nrAlloc;
+    i = TRI_IncModU64(i, array->_nrAlloc);
 #ifdef TRI_INTERNAL_STATS
     array->_nrProbesA++;
 #endif
@@ -1011,7 +1011,7 @@ int TRI_InsertKeyAssociativePointer2 (TRI_associative_pointer_t* array,
     i = hash % array->_nrAlloc;
     // search the table
     while (array->_table[i] != NULL && ! array->isEqualKeyElement(array, key, array->_table[i])) {
-      i = (i + 1) % array->_nrAlloc;
+      i = TRI_IncModU64(i, array->_nrAlloc);
 #ifdef TRI_INTERNAL_STATS
       array->_nrProbesA++;
 #endif
@@ -1046,7 +1046,7 @@ void* TRI_RemoveElementAssociativePointer (TRI_associative_pointer_t* array,
 
   // search the table
   while (array->_table[i] != NULL && ! array->isEqualElementElement(array, element, array->_table[i])) {
-    i = (i + 1) % array->_nrAlloc;
+    i = TRI_IncModU64(i, array->_nrAlloc);
 #ifdef TRI_INTERNAL_STATS
     array->_nrProbesD++;
 #endif
@@ -1063,7 +1063,7 @@ void* TRI_RemoveElementAssociativePointer (TRI_associative_pointer_t* array,
   array->_nrUsed--;
 
   // and now check the following places for items to move here
-  k = (i + 1) % array->_nrAlloc;
+  k = TRI_IncModU64(i, array->_nrAlloc);
 
   while (array->_table[k] != NULL) {
     uint64_t j = array->hashElement(array, array->_table[k]) % array->_nrAlloc;
@@ -1074,7 +1074,7 @@ void* TRI_RemoveElementAssociativePointer (TRI_associative_pointer_t* array,
       i = k;
     }
 
-    k = (k + 1) % array->_nrAlloc;
+    k = TRI_IncModU64(k, array->_nrAlloc);
   }
 
   // return success
@@ -1102,7 +1102,7 @@ void* TRI_RemoveKeyAssociativePointer (TRI_associative_pointer_t* array,
 
   // search the table
   while (array->_table[i] != NULL && ! array->isEqualKeyElement(array, key, array->_table[i])) {
-    i = (i + 1) % array->_nrAlloc;
+    i = TRI_IncModU64(i, array->_nrAlloc);
 #ifdef TRI_INTERNAL_STATS
     array->_nrProbesD++;
 #endif
@@ -1119,7 +1119,7 @@ void* TRI_RemoveKeyAssociativePointer (TRI_associative_pointer_t* array,
   array->_nrUsed--;
 
   // and now check the following places for items to move here
-  k = (i + 1) % array->_nrAlloc;
+  k = TRI_IncModU64(i, array->_nrAlloc);
 
   while (array->_table[k] != NULL) {
     uint64_t j = array->hashElement(array, array->_table[k]) % array->_nrAlloc;
@@ -1130,7 +1130,7 @@ void* TRI_RemoveKeyAssociativePointer (TRI_associative_pointer_t* array,
       i = k;
     }
 
-    k = (k + 1) % array->_nrAlloc;
+    k = TRI_IncModU64(k, array->_nrAlloc);
   }
 
   // return success
@@ -1179,7 +1179,7 @@ static void AddNewElementSynced (TRI_associative_synced_t* array, void* element)
   i = hash % array->_nrAlloc;
 
   while (array->_table[i] != NULL) {
-    i = (i + 1) % array->_nrAlloc;
+    i = TRI_IncModU64(i, array->_nrAlloc);
 #ifdef TRI_INTERNAL_STATS
     array->_nrProbesR++;
 #endif
@@ -1343,7 +1343,7 @@ void const* TRI_LookupByKeyAssociativeSynced (TRI_associative_synced_t* array,
   TRI_ReadLockReadWriteLock(&array->_lock);
 
   while (array->_table[i] != NULL && ! array->isEqualKeyElement(array, key, array->_table[i])) {
-    i = (i + 1) % array->_nrAlloc;
+    i = TRI_IncModU64(i, array->_nrAlloc);
 #ifdef TRI_INTERNAL_STATS
     array->_nrProbesF++;
 #endif
@@ -1380,7 +1380,7 @@ void const* TRI_LookupByElementAssociativeSynced (TRI_associative_synced_t* arra
   TRI_ReadLockReadWriteLock(&array->_lock);
 
   while (array->_table[i] != NULL && ! array->isEqualElementElement(array, element, array->_table[i])) {
-    i = (i + 1) % array->_nrAlloc;
+    i = TRI_IncModU64(i, array->_nrAlloc);
 #ifdef TRI_INTERNAL_STATS
     array->_nrProbesF++;
 #endif
@@ -1423,7 +1423,7 @@ void* TRI_InsertElementAssociativeSynced (TRI_associative_synced_t* array,
   TRI_WriteLockReadWriteLock(&array->_lock);
 
   while (array->_table[i] != NULL && ! array->isEqualElementElement(array, element, array->_table[i])) {
-    i = (i + 1) % array->_nrAlloc;
+    i = TRI_IncModU64(i, array->_nrAlloc);
 #ifdef TRI_INTERNAL_STATS
     array->_nrProbesA++;
 #endif
@@ -1480,7 +1480,7 @@ void* TRI_InsertKeyAssociativeSynced (TRI_associative_synced_t* array,
   TRI_WriteLockReadWriteLock(&array->_lock);
 
   while (array->_table[i] != NULL && ! array->isEqualKeyElement(array, key, array->_table[i])) {
-    i = (i + 1) % array->_nrAlloc;
+    i = TRI_IncModU64(i, array->_nrAlloc);
 #ifdef TRI_INTERNAL_STATS
     array->_nrProbesA++;
 #endif
@@ -1530,7 +1530,7 @@ void* TRI_RemoveElementAssociativeSynced (TRI_associative_synced_t* array,
   TRI_WriteLockReadWriteLock(&array->_lock);
 
   while (array->_table[i] != NULL && ! array->isEqualElementElement(array, element, array->_table[i])) {
-    i = (i + 1) % array->_nrAlloc;
+    i = TRI_IncModU64(i, array->_nrAlloc);
 #ifdef TRI_INTERNAL_STATS
     array->_nrProbesD++;
 #endif
@@ -1548,7 +1548,7 @@ void* TRI_RemoveElementAssociativeSynced (TRI_associative_synced_t* array,
   array->_nrUsed--;
 
   // and now check the following places for items to move here
-  k = (i + 1) % array->_nrAlloc;
+  k = TRI_IncModU64(i, array->_nrAlloc);
 
   while (array->_table[k] != NULL) {
     uint64_t j = array->hashElement(array, array->_table[k]) % array->_nrAlloc;
@@ -1559,7 +1559,7 @@ void* TRI_RemoveElementAssociativeSynced (TRI_associative_synced_t* array,
       i = k;
     }
 
-    k = (k + 1) % array->_nrAlloc;
+    k = TRI_IncModU64(k, array->_nrAlloc);
   }
 
   // return success
@@ -1590,7 +1590,7 @@ void* TRI_RemoveKeyAssociativeSynced (TRI_associative_synced_t* array,
   TRI_WriteLockReadWriteLock(&array->_lock);
 
   while (array->_table[i] != NULL && ! array->isEqualKeyElement(array, key, array->_table[i])) {
-    i = (i + 1) % array->_nrAlloc;
+    i = TRI_IncModU64(i, array->_nrAlloc);
 #ifdef TRI_INTERNAL_STATS
     array->_nrProbesD++;
 #endif
@@ -1608,7 +1608,7 @@ void* TRI_RemoveKeyAssociativeSynced (TRI_associative_synced_t* array,
   array->_nrUsed--;
 
   // and now check the following places for items to move here
-  k = (i + 1) % array->_nrAlloc;
+  k = TRI_IncModU64(i, array->_nrAlloc);
 
   while (array->_table[k] != NULL) {
     uint64_t j = array->hashElement(array, array->_table[k]) % array->_nrAlloc;
@@ -1619,7 +1619,7 @@ void* TRI_RemoveKeyAssociativeSynced (TRI_associative_synced_t* array,
       i = k;
     }
 
-    k = (k + 1) % array->_nrAlloc;
+    k = TRI_IncModU64(k, array->_nrAlloc);
   }
 
   // return success
diff --git a/lib/BasicsC/common.h b/lib/BasicsC/common.h
index e167f67dff..a70bdcb113 100644
--- a/lib/BasicsC/common.h
+++ b/lib/BasicsC/common.h
@@ -191,6 +191,19 @@ static inline void* CONST_CAST (void const* ptr) {
   return cnv.p;
 }
 
+////////////////////////////////////////////////////////////////////////////////
+/// @brief incrementing a uint64_t modulo a number with wraparound
+////////////////////////////////////////////////////////////////////////////////
+
+static inline uint64_t TRI_IncModU64(uint64_t i, uint64_t len) {
+  // Note that the dummy variable gives the compiler a (good) chance to
+  // use a conditional move instruction instead of a branch. This actually
+  // works on modern gcc.
+  uint64_t dummy;
+  dummy = (++i) - len;
+  return i < len ? i : dummy;
+}
+
 ////////////////////////////////////////////////////////////////////////////////
 /// @brief a wrapper for assert()
 ///