diff --git a/lisp/ob-C.el b/lisp/ob-C.el
index 4f33fc453..5f6c1cb1d 100644
--- a/lisp/ob-C.el
+++ b/lisp/ob-C.el
@@ -88,7 +88,9 @@ or `org-babel-execute:C++'."
 			(cond
 			 ((equal org-babel-c-variant 'c) ".c")
 			 ((equal org-babel-c-variant 'cpp) ".cpp"))))
-         (tmp-bin-file (org-babel-temp-file "C-bin-"))
+         (tmp-bin-file (org-babel-temp-file
+			"C-bin-"
+			(if (equal system-type 'windows-nt) ".exe" "")))
          (cmdline (cdr (assoc :cmdline params)))
          (flags (cdr (assoc :flags params)))
          (full-body (org-babel-C-expand body params))