diff --git a/tests/c-api/test-just-header-cxx.cpp b/tests/c-api/test-just-header-cxx.cpp
index 611d2fbb8..876d557b5 100644
--- a/tests/c-api/test-just-header-cxx.cpp
+++ b/tests/c-api/test-just-header-cxx.cpp
@@ -30,6 +30,5 @@ int
 main (int argc, char *argv[])
 {
   guestfs_h *g = guestfs_create ();
-  (void) g; /* trick shamelessly stolen from gnulib */
-  return 0;
+  return g != NULL ? 0 : 1;
 }
diff --git a/tests/c-api/test-just-header.c b/tests/c-api/test-just-header.c
index 233577139..98c7ebd9a 100644
--- a/tests/c-api/test-just-header.c
+++ b/tests/c-api/test-just-header.c
@@ -26,6 +26,5 @@ int
 main (int argc, char *argv[])
 {
   guestfs_h *g = guestfs_create ();
-  (void) g; /* trick shamelessly stolen from gnulib */
-  return 0;
+  return g != NULL ? 0 : 1;
 }