diff --git a/lib/CodeGen/SelectionDAG/LegalizeTypes.cpp b/lib/CodeGen/SelectionDAG/LegalizeTypes.cpp
index 0573b6dd356..84dfdc7a7ff 100644
--- a/lib/CodeGen/SelectionDAG/LegalizeTypes.cpp
+++ b/lib/CodeGen/SelectionDAG/LegalizeTypes.cpp
@@ -385,6 +385,7 @@ void DAGTypeLegalizer::RemapValue(SDValue &N) {
     // replaced with other values.
     RemapValue(I->second);
     N = I->second;
+    assert(N.getNode()->getNodeId() != NewNode && "Mapped to unanalyzed node!");
   }
 }