diff --git a/arangod/RocksDBEngine/RocksDBKey.h b/arangod/RocksDBEngine/RocksDBKey.h
index 855f0e592b..7b52cd2e72 100644
--- a/arangod/RocksDBEngine/RocksDBKey.h
+++ b/arangod/RocksDBEngine/RocksDBKey.h
@@ -40,7 +40,7 @@ namespace arangodb {
 class RocksDBKey {
  public:
   RocksDBKey() = delete;
-  RocksDBKey(rocksdb::Slice slice)
+  explicit RocksDBKey(rocksdb::Slice slice)
       : _type(static_cast<RocksDBEntryType>(slice.data()[0])),
         _buffer(slice.data(), slice.size()) {}
 
diff --git a/arangod/VocBase/Methods/Indexes.cpp b/arangod/VocBase/Methods/Indexes.cpp
index 9f811d87af..4ff77f5d13 100644
--- a/arangod/VocBase/Methods/Indexes.cpp
+++ b/arangod/VocBase/Methods/Indexes.cpp
@@ -106,7 +106,6 @@ arangodb::Result Indexes::getAll(arangodb::LogicalCollection const* collection,
   if (ServerState::instance()->isCoordinator()) {
     std::string const databaseName(collection->dbName());
     std::string const cid = collection->cid_as_string();
-    std::string const collectionName(collection->name());
 
     auto c = ClusterInfo::instance()->getCollection(databaseName, cid);
     c->getIndexesVPack(tmp, withFigures, false);
@@ -126,7 +125,6 @@ arangodb::Result Indexes::getAll(arangodb::LogicalCollection const* collection,
 
     // READ-LOCK start
     trx.lockRead();
-    std::string const collectionName(collection->name());
 
     // get list of indexes
     auto indexes = collection->getIndexes();
@@ -237,7 +235,7 @@ static Result EnsureIndexLocal(arangodb::LogicalCollection* collection,
     // TODO Encapsulate in try{}catch(){} instead of errno()
     try {
       idx = collection->createIndex(&trx, definition, created);
-    } catch (arangodb::basics::Exception e) {
+    } catch (arangodb::basics::Exception const& e) {
       return Result(e.code());
     }
     if (idx == nullptr) {
@@ -365,7 +363,6 @@ Result Indexes::ensureIndex(arangodb::LogicalCollection* collection,
 
   // ensure an index, coordinator case
   if (ServerState::instance()->isCoordinator()) {
-    std::string errorMsg;
     VPackBuilder tmp;
 #ifdef USE_ENTERPRISE
     Result res =