diff --git a/string/bug-strncat1.c b/string/bug-strncat1.c
index 65a7ed58c2..cdd2141191 100644
--- a/string/bug-strncat1.c
+++ b/string/bug-strncat1.c
@@ -1,9 +1,16 @@
 #undef __USE_STRING_INLINES
 #define __USE_STRING_INLINES
+#include <sys/cdefs.h>
+#include <libc-diag.h>
+#if __GNUC_PREREQ (8, 0)
+/* GCC warns about strncat truncating output; this is deliberately
+   tested here.  If fortify is enabled, it is also triggered by the
+   wrappers. */
+DIAG_IGNORE_NEEDS_COMMENT (8, "-Wstringop-truncation");
+#endif
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
-#include <libc-diag.h>
 
 char d[3] = "\0\1\2";
 
@@ -11,11 +18,6 @@ int
 main (void)
 {
   DIAG_PUSH_NEEDS_COMMENT;
-#if __GNUC_PREREQ (8, 0)
-  /* GCC 8 warns about strncat truncating output; this is deliberately
-     tested here.  */
-  DIAG_IGNORE_NEEDS_COMMENT (8, "-Wstringop-truncation");
-#endif
   strncat (d, "\5\6", 1);
   DIAG_POP_NEEDS_COMMENT;
   if (d[0] != '\5')