diff --git a/compiler/optimizing/nodes.cc b/compiler/optimizing/nodes.cc
index 207c605..1d7e678 100644
--- a/compiler/optimizing/nodes.cc
+++ b/compiler/optimizing/nodes.cc
@@ -194,6 +194,11 @@
     }
     pre_header->AddSuccessor(header);
   }
+
+  // Make sure the second predecessor of a loop header is the back edge.
+  if (header->GetPredecessors().Get(1) != info->GetBackEdges().Get(0)) {
+    header->SwapPredecessors();
+  }
 }
 
 void HGraph::SimplifyCFG() {