diff --git a/src/rdb.c b/src/rdb.c
index 8cb217b73..381991881 100644
--- a/src/rdb.c
+++ b/src/rdb.c
@@ -84,7 +84,7 @@ void rdbReportError(int corruption_error, int linenum, char *reason, ...) {
     exit(1);
 }
 
-static int rdbWriteRaw(rio *rdb, void *p, size_t len) {
+static ssize_t rdbWriteRaw(rio *rdb, void *p, size_t len) {
     if (rdb && rioWrite(rdb,p,len) == 0)
         return -1;
     return len;