diff --git a/lib/CodeGen/LLVMTargetMachine.cpp b/lib/CodeGen/LLVMTargetMachine.cpp
index 9a35109..e4ad872 100644
--- a/lib/CodeGen/LLVMTargetMachine.cpp
+++ b/lib/CodeGen/LLVMTargetMachine.cpp
@@ -140,7 +140,7 @@
   if (addPreEmitPass(PM, Fast) && PrintMachineCode)
     PM.add(createMachineFunctionPrinterPass(cerr));
 
-  if (AlignLoops && !OptimizeForSize)
+  if (AlignLoops && !Fast && !OptimizeForSize)
     PM.add(createLoopAlignerPass());
 
   switch (FileType) {