diff --git a/CMake/CurlTests.c b/CMake/CurlTests.c
index 04d5e7e469709d607c29d81e82599f4e0eacd41e..3c712325fd92169c399bd4df762d9ba3d4a77317 100644
--- a/CMake/CurlTests.c
+++ b/CMake/CurlTests.c
@@ -139,7 +139,7 @@ int main(void)
   rc = gethostbyname_r(address, &h, &hdata);
 #elif defined(HAVE_GETHOSTBYNAME_R_5) || \
       defined(HAVE_GETHOSTBYNAME_R_5_REENTRANT)
-  rc = gethostbyname_r(address, &h, buffer, 8192, 0, &h_errnop);
+  rc = gethostbyname_r(address, &h, buffer, 8192, &h_errnop);
   (void)hp; /* not used for test */
 #elif defined(HAVE_GETHOSTBYNAME_R_6) || \
       defined(HAVE_GETHOSTBYNAME_R_6_REENTRANT)