diff --git a/llvm/include/llvm/ADT/STLExtras.h b/llvm/include/llvm/ADT/STLExtras.h
index e11d6cac7685e..eb441bb31c9bc 100644
--- a/llvm/include/llvm/ADT/STLExtras.h
+++ b/llvm/include/llvm/ADT/STLExtras.h
@@ -1194,7 +1194,8 @@ class indexed_accessor_iterator
     return index - rhs.index;
   }
   bool operator==(const indexed_accessor_iterator &rhs) const {
-    return base == rhs.base && index == rhs.index;
+    assert(base == rhs.base && "incompatible iterators");
+    return index == rhs.index;
   }
   bool operator<(const indexed_accessor_iterator &rhs) const {
     assert(base == rhs.base && "incompatible iterators");