diff --git a/src/common/kiwix/reader.cpp b/src/common/kiwix/reader.cpp
index 8e52f8a5..0f799867 100644
--- a/src/common/kiwix/reader.cpp
+++ b/src/common/kiwix/reader.cpp
@@ -60,7 +60,7 @@ static char charFromHex(std::string a) {
 
 void unescapeUrl(string &url) {
   std::string::size_type pos = 0;
-  while ((pos = url.find('%', pos + 1)) != std::string::npos &&
+  while ((pos = url.find('%', pos ? pos + 1 : pos)) != std::string::npos &&
 	 pos + 3 <= url.length()) {
     url.replace(pos, 3, 1, charFromHex(url.substr(pos + 1, 2)));
   }