diff --git a/lib/ExecutionEngine/JIT/JIT.cpp b/lib/ExecutionEngine/JIT/JIT.cpp
index 6940d85..0f98ddc 100644
--- a/lib/ExecutionEngine/JIT/JIT.cpp
+++ b/lib/ExecutionEngine/JIT/JIT.cpp
@@ -553,6 +553,8 @@
   if (void *Addr = getPointerToGlobalIfAvailable(F))
     return Addr;   // Check if function already code gen'd
 
+  MutexGuard locked(lock);
+
   // Make sure we read in the function if it exists in this Module.
   if (F->hasNotBeenReadFromBitcode()) {
     // Determine the module provider this function is provided by.
@@ -578,8 +580,6 @@
       return Addr;
   }
 
-  MutexGuard locked(lock);
-
   if (F->isDeclaration()) {
     bool AbortOnFailure = F->getLinkage() != GlobalValue::ExternalWeakLinkage;
     void *Addr = getPointerToNamedFunction(F->getName(), AbortOnFailure);