diff --git a/lib/fs/readlink/readlinknul.c b/lib/fs/readlink/readlinknul.c
index 4baea0d01..b0fc2a786 100644
--- a/lib/fs/readlink/readlinknul.c
+++ b/lib/fs/readlink/readlinknul.c
@@ -7,7 +7,8 @@
 #include "fs/readlink/readlinknul.h"
 
 #include <stddef.h>
+#include <sys/types.h>
 
 
-extern inline int readlinknul(const char *restrict link, char *restrict buf,
+extern inline ssize_t readlinknul(const char *restrict link, char *restrict buf,
     size_t size);
diff --git a/lib/fs/readlink/readlinknul.h b/lib/fs/readlink/readlinknul.h
index b063a508b..606c2e112 100644
--- a/lib/fs/readlink/readlinknul.h
+++ b/lib/fs/readlink/readlinknul.h
@@ -22,12 +22,12 @@
 
 
 ATTR_STRING(1)
-inline int readlinknul(const char *restrict link, char *restrict buf,
+inline ssize_t readlinknul(const char *restrict link, char *restrict buf,
     size_t size);
 
 
 // Similar to readlink(2), but terminate the string.
-inline int
+inline ssize_t
 readlinknul(const char *restrict link, char *restrict buf, size_t size)
 {
 	size_t   ulen;