diff --git a/polly/lib/CodeGen/IslCodeGeneration.cpp b/polly/lib/CodeGen/IslCodeGeneration.cpp
index f5599ee..68ed943 100644
--- a/polly/lib/CodeGen/IslCodeGeneration.cpp
+++ b/polly/lib/CodeGen/IslCodeGeneration.cpp
@@ -605,6 +605,10 @@
     assert(!S.getRegion().isTopLevelRegion() &&
            "Top level regions are not supported");
 
+    // Build the alias scopes for annotations first.
+    if (PollyAnnotateAliasScopes)
+      Annotator.buildAliasScopes(S);
+
     BasicBlock *EnteringBB = simplifyRegion(&S, this);
     PollyIRBuilder Builder = createPollyIRBuilder(EnteringBB, Annotator);