diff --git a/src/ecmascript/spidermonkey/navigator.c b/src/ecmascript/spidermonkey/navigator.c
index dec0dfb11..a96e55076 100644
--- a/src/ecmascript/spidermonkey/navigator.c
+++ b/src/ecmascript/spidermonkey/navigator.c
@@ -187,7 +187,7 @@ navigator_get_property_userAgent(JSContext *ctx, unsigned int argc, JS::Value *v
 
 	if (*optstr && strcmp(optstr, " ")) {
 		char *ustr, ts[64] = "";
-		static unsigned char custr[256];
+		static char custr[256];
 		/* TODO: Somehow get the terminal in which the
 		 * document is actually being displayed.  */
 		struct terminal *term = get_default_terminal();