diff --git a/test/Analysis/cstring-syntax-cxx.cpp b/test/Analysis/cstring-syntax-cxx.cpp
index bae3d0a..39c978a 100644
--- a/test/Analysis/cstring-syntax-cxx.cpp
+++ b/test/Analysis/cstring-syntax-cxx.cpp
@@ -15,3 +15,8 @@
   X c = a + b;
 }
 
+// Ensure we don't crash on custom-defined strncat.
+char strncat ();
+int main () {
+  return strncat ();
+}
\ No newline at end of file