diff --git a/src/main.c b/src/main.c
index b5c1d89b7..261bb880a 100644
--- a/src/main.c
+++ b/src/main.c
@@ -3289,6 +3289,7 @@ static void go_sleep(long ms)
 
 static size_t my_fwrite(void *buffer, size_t sz, size_t nmemb, void *stream)
 {
+  int res;
   size_t rc;
   struct OutStruct *out=(struct OutStruct *)stream;
   struct Configurable *config = out->config;
@@ -3323,8 +3324,8 @@ static size_t my_fwrite(void *buffer, size_t sz, size_t nmemb, void *stream)
 
   if(config->nobuffer) {
     /* disable output buffering */
-    rc = fflush(out->stream);
-    if(rc) {
+    res = fflush(out->stream);
+    if(res) {
       /* return a value that isn't the same as sz * nmemb */
       rc = (0 == (sz * nmemb)) ? 1 : 0;
       return rc; /* failure */