diff --git a/ccan/sparse_bsearch/sparse_bsearch.c b/ccan/sparse_bsearch/sparse_bsearch.c
index 6db7cc24ec84a58d7a732d65cdd5f485bb6a2077..36330679ef908ff4ddd06b53026adb183b68249f 100644
--- a/ccan/sparse_bsearch/sparse_bsearch.c
+++ b/ccan/sparse_bsearch/sparse_bsearch.c
@@ -1,4 +1,5 @@
 /* Licensed under LGPLv2+ - see LICENSE file for details */
+#include <sys/types.h> //for ssize_t definition
 #include "sparse_bsearch.h"
 
 void *_sparse_bsearch(const void *key, const void *base,