diff --git a/indra/newview/llweb.cpp b/indra/newview/llweb.cpp
index 5bca8db8e..91440c6e0 100644
--- a/indra/newview/llweb.cpp
+++ b/indra/newview/llweb.cpp
@@ -71,13 +71,29 @@ void LLWeb::loadURLExternal(const std::string& url)
 // static
 std::string LLWeb::curlEscape(const std::string& url)
 {
+	static const char hex[] = "0123456789ABCDEF";
 	std::stringstream escaped_url;
 	for (std::string::const_iterator iter = url.begin(); iter != url.end(); ++iter)
 	{
-	  if (isalnum(*iter))
-		escaped_url << *iter;
-	  else
-		escaped_url << '%' << std::hex << std::setfill('0') << std::setw(2) << std::uppercase << (int)*iter;
+		switch(*iter) {
+			case '0': case '1': case '2': case '3': case '4':
+			case '5': case '6': case '7': case '8': case '9':
+			case 'a': case 'b': case 'c': case 'd': case 'e':
+			case 'f': case 'g': case 'h': case 'i': case 'j':
+			case 'k': case 'l': case 'm': case 'n': case 'o':
+			case 'p': case 'q': case 'r': case 's': case 't':
+			case 'u': case 'v': case 'w': case 'x': case 'y': case 'z':
+			case 'A': case 'B': case 'C': case 'D': case 'E':
+			case 'F': case 'G': case 'H': case 'I': case 'J':
+			case 'K': case 'L': case 'M': case 'N': case 'O':
+			case 'P': case 'Q': case 'R': case 'S': case 'T':
+			case 'U': case 'V': case 'W': case 'X': case 'Y': case 'Z':
+				escaped_url << (*iter);
+				break;
+			default:
+				unsigned char c = (unsigned char)(*iter);
+				escaped_url << '%' << hex[c>>4] << hex[c&0xF];
+		}
 	}
 	return escaped_url.str();
 }