diff --git a/lib/config-plan9.h b/lib/config-plan9.h
index 616b8e2658..5303ab3399 100644
--- a/lib/config-plan9.h
+++ b/lib/config-plan9.h
@@ -108,6 +108,7 @@
 #define HAVE_SOCKADDR_IN6_SIN6_SCOPE_ID 1
 #define HAVE_SOCKET 1
 #define HAVE_STDBOOL_H 1
+#define HAVE_STDINT_H 1
 #define HAVE_STRCASECMP 1
 #define HAVE_STRDUP 1
 #define HAVE_STRUCT_TIMEVAL 1