diff --git a/configure.in b/configure.in
index 4ea5965..49100ff 100644
--- a/configure.in
+++ b/configure.in
@@ -518,6 +518,7 @@ AC_CHECK_FUNC([mkstemp],,[AC_MSG_ERROR([needs mkstemp])])
 #
 AC_MSG_CHECKING([for strerror])
 AC_TRY_LINK([
+#include <string.h>
 char *blubb() { return (char *) strerror (42); }
 ],[
 (void) blubb();