Wrap stdint.h inside #ifdef HAVE_STDINT_H.
diff --git a/regress/misc/kexfuzz/kexfuzz.c b/regress/misc/kexfuzz/kexfuzz.c
index 0a4eabc..e6751d3 100644
--- a/regress/misc/kexfuzz/kexfuzz.c
+++ b/regress/misc/kexfuzz/kexfuzz.c
@@ -10,7 +10,9 @@
 #include <sys/types.h>
 #include <sys/param.h>
 #include <stdio.h>
-#include <stdint.h>
+#ifdef HAVE_STDINT_H
+# include <stdint.h>
+#endif
 #include <stdlib.h>
 #include <string.h>
 #include <unistd.h>