diff --git a/ext/standard/exec.c b/ext/standard/exec.c
index db4f3f6a390..0f00df26650 100644
--- a/ext/standard/exec.c
+++ b/ext/standard/exec.c
@@ -322,12 +322,12 @@ PHPAPI char *php_escape_shell_cmd(char *str)
 			case '\x0A': /* excluding these two */
 			case '\xFF':
 #ifdef PHP_WIN32
-			/* since Windows does not allow us to escape these chars, just remove them */
+			/* This is Windows specific for enviromental variables */
 			case '%':
-				cmd[y++] = ' ';
-				break;
-#endif
+				cmd[y++] = '^';
+#else
 				cmd[y++] = '\\';
+#endif
 				/* fall-through */
 			default:
 				cmd[y++] = str[x];