diff --git a/docs/examples/externalsocket.c b/docs/examples/externalsocket.c
index 1b6c9209dd36ebcb3aa6157dead816effc5f10b5..8152515b6e33026a8fa4d9fa8b592183f21b56c4 100644
--- a/docs/examples/externalsocket.c
+++ b/docs/examples/externalsocket.c
@@ -54,7 +54,7 @@
 
 static size_t write_data(void *ptr, size_t size, size_t nmemb, void *stream)
 {
-  int written = fwrite(ptr, size, nmemb, (FILE *)stream);
+  size_t written = fwrite(ptr, size, nmemb, (FILE *)stream);
   return written;
 }