diff --git a/CHANGELOG b/CHANGELOG
index 86812d1474..abfd1b858e 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -1,3 +1,9 @@
+devel
+-----
+
+* don't let read-only transactions block the WAL collector 
+
+
 v3.2.alpha2 (2017-02-20)
 ------------------------
 
diff --git a/arangod/MMFiles/MMFilesLogfileManager.cpp b/arangod/MMFiles/MMFilesLogfileManager.cpp
index 9e778f7907..b1f7cac313 100644
--- a/arangod/MMFiles/MMFilesLogfileManager.cpp
+++ b/arangod/MMFiles/MMFilesLogfileManager.cpp
@@ -535,7 +535,7 @@ void MMFilesLogfileManager::unprepare() {
 }
 
 // registers a transaction
-int MMFilesLogfileManager::registerTransaction(TRI_voc_tid_t transactionId) {
+int MMFilesLogfileManager::registerTransaction(TRI_voc_tid_t transactionId, bool isReadOnlyTransaction) {
   auto lastCollectedId = _lastCollectedId.load();
   auto lastSealedId = _lastSealedId.load();
 
@@ -546,6 +546,16 @@ int MMFilesLogfileManager::registerTransaction(TRI_voc_tid_t transactionId) {
     
   TRI_ASSERT(lastCollectedId <= lastSealedId);
 
+  if (isReadOnlyTransaction) {
+    // in case this is a read-only transaction, we are sure that the transaction can
+    // only see committed data (as itself it will not write anything, and write transactions
+    // run exclusively). we thus can allow the WAL collector to already seal and collect
+    // logfiles. the only thing that needs to be ensured for read-only transactions is
+    // that a logfile does not get thrown away while the read-only transaction is 
+    // ongoing
+    lastSealedId = 0;
+  }
+
   try {
     auto data = std::make_unique<MMFilesTransactionData>(lastCollectedId, lastSealedId);
     TransactionManagerFeature::MANAGER->registerTransaction(transactionId, std::move(data));
diff --git a/arangod/MMFiles/MMFilesLogfileManager.h b/arangod/MMFiles/MMFilesLogfileManager.h
index 00995adc8b..1b96176ae3 100644
--- a/arangod/MMFiles/MMFilesLogfileManager.h
+++ b/arangod/MMFiles/MMFilesLogfileManager.h
@@ -68,8 +68,8 @@ struct MMFilesTransactionData final : public TransactionData {
   MMFilesTransactionData() = delete;
   MMFilesTransactionData(MMFilesWalLogfile::IdType lastCollectedId, MMFilesWalLogfile::IdType lastSealedId) :
       lastCollectedId(lastCollectedId), lastSealedId(lastSealedId) {}
-  MMFilesWalLogfile::IdType lastCollectedId;
-  MMFilesWalLogfile::IdType lastSealedId;
+  MMFilesWalLogfile::IdType const lastCollectedId;
+  MMFilesWalLogfile::IdType const lastSealedId;
 };
 
 struct MMFilesLogfileManagerState {
@@ -218,7 +218,7 @@ class MMFilesLogfileManager final : public application_features::ApplicationFeat
   }
 
   // registers a transaction
-  int registerTransaction(TRI_voc_tid_t);
+  int registerTransaction(TRI_voc_tid_t id, bool isReadOnlyTransaction);
 
   // return the set of dropped collections
   /// this is used during recovery and not used afterwards
@@ -459,8 +459,8 @@ class MMFilesLogfileManager final : public application_features::ApplicationFeat
 
   bool _allowOversizeEntries = true;
   bool _useMLock = false;
-  std::string _directory = "";
-  uint32_t _historicLogfiles = 10;
+  std::string _directory;
+  uint32_t _historicLogfiles = 10; 
   bool _ignoreLogfileErrors = false;
   bool _ignoreRecoveryErrors = false;
   uint64_t _flushTimeout = 15000;
diff --git a/arangod/MMFiles/MMFilesTransactionState.cpp b/arangod/MMFiles/MMFilesTransactionState.cpp
index bb8ce48509..a769ee866d 100644
--- a/arangod/MMFiles/MMFilesTransactionState.cpp
+++ b/arangod/MMFiles/MMFilesTransactionState.cpp
@@ -104,8 +104,8 @@ int MMFilesTransactionState::beginTransaction(transaction::Hints hints, int nest
     _id = TRI_NewTickServer();
 
     // register a protector
-    int res = logfileManager->registerTransaction(_id);
-
+    int res = logfileManager->registerTransaction(_id, isReadOnlyTransaction());
+ 
     if (res != TRI_ERROR_NO_ERROR) {
       return res;
     }