diff --git a/lib/Lex/Preprocessor.cpp b/lib/Lex/Preprocessor.cpp
index 54c1748..5d9fc95 100644
--- a/lib/Lex/Preprocessor.cpp
+++ b/lib/Lex/Preprocessor.cpp
@@ -98,7 +98,9 @@
        Macros.begin(), E = Macros.end(); I != E; ++I) {
     // We don't need to free the MacroInfo objects directly.  These
     // will be released when the BumpPtrAllocator 'BP' object gets
-    // destroyed.
+    // destroyed. We still need to run the dstor, however, to free
+    // memory alocated by MacroInfo.
+    I->second->~MacroInfo();    
     I->first->setHasMacroDefinition(false);
   }