diff --git a/lib/CodeGen/LiveStackAnalysis.cpp b/lib/CodeGen/LiveStackAnalysis.cpp
index 9358c10..2baf699 100644
--- a/lib/CodeGen/LiveStackAnalysis.cpp
+++ b/lib/CodeGen/LiveStackAnalysis.cpp
@@ -26,6 +26,7 @@
 
 void LiveStacks::getAnalysisUsage(AnalysisUsage &AU) const {
   AU.setPreservesAll();
+  MachineFunctionPass::getAnalysisUsage(AU);
 }
 
 void LiveStacks::releaseMemory() {