diff --git a/lib/Analysis/AssumeBundleQueries.cpp b/lib/Analysis/AssumeBundleQueries.cpp
index 273b38a9567..9cb5b10570b 100644
--- a/lib/Analysis/AssumeBundleQueries.cpp
+++ b/lib/Analysis/AssumeBundleQueries.cpp
@@ -88,9 +88,11 @@ void llvm::fillMapFromAssume(CallInst &AssumeCI, RetainedKnowledgeMap &Result) {
       Result[Key][&Assume] = {0, 0};
       continue;
     }
-    unsigned Val = cast<ConstantInt>(
-                       getValueFromBundleOpInfo(Assume, Bundles, ABA_Argument))
-                       ->getZExtValue();
+    auto *CI = dyn_cast<ConstantInt>(
+        getValueFromBundleOpInfo(Assume, Bundles, ABA_Argument));
+    if (!CI)
+      continue;
+    unsigned Val = CI->getZExtValue();
     auto Lookup = Result.find(Key);
     if (Lookup == Result.end() || !Lookup->second.count(&Assume)) {
       Result[Key][&Assume] = {Val, Val};
diff --git a/unittests/Analysis/AssumeBundleQueriesTest.cpp b/unittests/Analysis/AssumeBundleQueriesTest.cpp
index 946368e1cb9..a66e365f237 100644
--- a/unittests/Analysis/AssumeBundleQueriesTest.cpp
+++ b/unittests/Analysis/AssumeBundleQueriesTest.cpp
@@ -383,6 +383,15 @@ TEST(AssumeQueryAPI, fillMapFromAssume) {
                                        "(nonnull|align|dereferenceable)"));
         ASSERT_TRUE(FindExactlyAttributes(Map, Old, ""));
       }));
+  Tests.push_back(std::make_pair(
+      "call void @llvm.assume(i1 true) [\"align\"(i8* undef, i32 undef)]",
+      [](Instruction *I) {
+        // Don't crash but don't learn from undef.
+        RetainedKnowledgeMap Map;
+        fillMapFromAssume(*cast<IntrinsicInst>(I), Map);
+
+        ASSERT_TRUE(Map.empty());
+      }));
   RunTest(Head, Tail, Tests);
 }