diff --git a/clang/lib/AST/ExprConstant.cpp b/clang/lib/AST/ExprConstant.cpp
index bac2356cc43f..135e70e96ad6 100644
--- a/clang/lib/AST/ExprConstant.cpp
+++ b/clang/lib/AST/ExprConstant.cpp
@@ -133,7 +133,11 @@ namespace {
 
     E = E->IgnoreParens();
     // If we're doing a variable assignment from e.g. malloc(N), there will
-    // probably be a cast of some kind. Ignore it.
+    // probably be a cast of some kind. In exotic cases, we might also see a
+    // top-level ExprWithCleanups. Ignore them either way.
+    if (const auto *EC = dyn_cast<ExprWithCleanups>(E))
+      E = EC->getSubExpr()->IgnoreParens();
+
     if (const auto *Cast = dyn_cast<CastExpr>(E))
       E = Cast->getSubExpr()->IgnoreParens();
 
diff --git a/clang/test/CodeGenCXX/alloc-size.cpp b/clang/test/CodeGenCXX/alloc-size.cpp
index 137d4543ddcd..275ffe6dca9a 100644
--- a/clang/test/CodeGenCXX/alloc-size.cpp
+++ b/clang/test/CodeGenCXX/alloc-size.cpp
@@ -88,3 +88,15 @@ int callMemberCalloc() {
   // CHECK: ret i32 32
   return __builtin_object_size(C().my_calloc(16, 2), 0);
 }
+
+struct D {
+  ~D();
+  void *my_malloc(int N) __attribute__((alloc_size(2)));
+};
+
+// CHECK-LABEL: define i32 @_Z20callExprWithCleanupsv
+int callExprWithCleanups() {
+  int *const p = (int *)D().my_malloc(3);
+  // CHECK: ret i32 3
+  return __builtin_object_size(p, 0);
+}