diff --git a/src/rpcblockchain.cpp b/src/rpcblockchain.cpp
index 92f0c07a8..39f62dfa1 100644
--- a/src/rpcblockchain.cpp
+++ b/src/rpcblockchain.cpp
@@ -1419,8 +1419,8 @@ UniValue getchaintips(const UniValue& params, bool fHelp)
        of another block.  */
     static pthread_mutex_t mutex; static int32_t didinit;
     if ( didinit == 0 )
-        portable_mutex_init(&mutex);
-    portable_mutex_lock(&mutex);
+        pthread_mutex_init(&mutex);
+    pthread_mutex_lock(&mutex);
     std::set<const CBlockIndex*, CompareBlocksByHeight> setTips;
     int32_t n = 0;
     BOOST_FOREACH(const PAIRTYPE(const uint256, CBlockIndex*)& item, mapBlockIndex)
@@ -1440,7 +1440,7 @@ UniValue getchaintips(const UniValue& params, bool fHelp)
             setTips.erase(pprev);
     }
     fprintf(stderr,"iterations getchaintips %d\n",n);
-    portable_mutex_unlock(&mutex);
+    pthread_mutex_unlock(&mutex);
 
     // Always report the currently active tip.
     setTips.insert(chainActive.LastTip());