diff --git a/arangod/Indexes/Index.cpp b/arangod/Indexes/Index.cpp
index 8eeb2e9eb7..9b6e6e7cc4 100644
--- a/arangod/Indexes/Index.cpp
+++ b/arangod/Indexes/Index.cpp
@@ -508,6 +508,10 @@ bool Index::canUseConditionPart (triagens::aql::AstNode const* access,
                                  triagens::aql::Variable const* reference) const {
 
   if (_sparse) {
+    if (op->type == triagens::aql::NODE_TYPE_OPERATOR_BINARY_NIN) {
+      return false;
+    }
+
     if (op->type == triagens::aql::NODE_TYPE_OPERATOR_BINARY_IN &&
         other->type == triagens::aql::NODE_TYPE_EXPANSION) {
       // value IN a.b
@@ -525,15 +529,23 @@ bool Index::canUseConditionPart (triagens::aql::AstNode const* access,
         return false;
       }
 
-      if (other->isNullValue()) {
+      if (op->type == triagens::aql::NODE_TYPE_OPERATOR_BINARY_LT ||
+          op->type == triagens::aql::NODE_TYPE_OPERATOR_BINARY_LE) {
+        // <  and  <= are not supported with sparse indexes as this may include null values
         return false;
       }
 
-      TRI_ASSERT_EXPENSIVE(other->isConstant());
+      if (other->isNullValue() &&
+          (op->type == triagens::aql::NODE_TYPE_OPERATOR_BINARY_EQ ||
+           op->type == triagens::aql::NODE_TYPE_OPERATOR_BINARY_GE)) {
+        // ==  and  >= null are not supported with sparse indexes for the same reason
+        return false;
+      }
 
       if (op->type == triagens::aql::NODE_TYPE_OPERATOR_BINARY_IN &&
           other->type == triagens::aql::NODE_TYPE_ARRAY) {
         size_t const n = other->numMembers();
+
         for (size_t i = 0; i < n; ++i) {
           if (other->getMemberUnchecked(i)->isNullValue()) {
             return false;
diff --git a/arangod/Indexes/SkiplistIndex.cpp b/arangod/Indexes/SkiplistIndex.cpp
index bdad13b5cb..f3a2d4bdf8 100644
--- a/arangod/Indexes/SkiplistIndex.cpp
+++ b/arangod/Indexes/SkiplistIndex.cpp
@@ -1203,7 +1203,12 @@ bool SkiplistIndex::supportsFilterCondition (triagens::aql::AstNode const* node,
     return true;
   }
 
-  if (attributesCovered > 0) {
+  if (attributesCovered > 0 &&
+      (! _sparse || (_sparse && attributesCovered == _fields.size()))) {
+    // if the condition contains at least one index attribute and is not sparse,
+    // or the index is sparse and all attributes are covered by the condition,
+    // then it can be used (note: additional checks for condition parts in 
+    // sparse indexes are contained in Index::canUseConditionPart)
     estimatedItems = static_cast<size_t>((std::max)(static_cast<size_t>(estimatedCost * values), static_cast<size_t>(1)));
     estimatedCost *= static_cast<double>(values);
     return true;
diff --git a/js/server/tests/aql-optimizer-indexes.js b/js/server/tests/aql-optimizer-indexes.js
index b5c2bfc0b6..8ce949b4e0 100644
--- a/js/server/tests/aql-optimizer-indexes.js
+++ b/js/server/tests/aql-optimizer-indexes.js
@@ -2464,34 +2464,22 @@ function optimizerIndexesTestSuite () {
       c.ensureSkiplist("value2", "value3", { sparse: true });
 
       var queries = [
-        ["FOR i IN " + c.name() + " FILTER i.value2 == 2 RETURN i.value", true],
-        ["FOR i IN " + c.name() + " FILTER i.value3 == 2 RETURN i.value", false]
+        "FOR i IN " + c.name() + " FILTER i.value2 == 2 RETURN i.value",
+        "FOR i IN " + c.name() + " FILTER i.value3 == 2 RETURN i.value"
       ];
 
       queries.forEach(function(query) {
-        var plan = AQL_EXPLAIN(query[0]).plan;
+        var plan = AQL_EXPLAIN(query).plan;
         var nodeTypes = plan.nodes.map(function(node) {
           return node.type;
         });
-        var results;
-
-        if (query[1]) {
-          // Can use Index
-          assertNotEqual(-1, nodeTypes.indexOf("IndexNode"), query[0]);
-          results = AQL_EXECUTE(query[0]);
-          assertEqual([ 2 ], results.json, query[0]);
-          assertTrue(results.stats.scannedIndex > 0);
-          assertEqual(0, results.stats.scannedFull);
-        }
-        else {
-          // Cannot use Index
-          assertEqual(-1, nodeTypes.indexOf("IndexNode"), query[0]);
-          results = AQL_EXECUTE(query[0]);
-          assertEqual([ 2 ], results.json, query[0]);
-          assertTrue(results.stats.scannedFull > 0);
-          assertEqual(0, results.stats.scannedIndex);
-        }
 
+        // Cannot use Index
+        assertEqual(-1, nodeTypes.indexOf("IndexNode"), query);
+        var results = AQL_EXECUTE(query);
+        assertEqual([ 2 ], results.json, query);
+        assertTrue(results.stats.scannedFull > 0);
+        assertEqual(0, results.stats.scannedIndex);
       });
     },