diff --git a/src/string.cpp b/src/string.cpp
index a90388b..eb8bb9f 100644
--- a/src/string.cpp
+++ b/src/string.cpp
@@ -138,10 +138,14 @@ static void _l33t(strlist_t& list, const std::string& a, int pos) {
 	}
 }
 
-strlist_t l33twords(const std::string& str) {
+strlist_t l33twords(std::string str) {
 
 	strlist_t list;
 
+	// "l" is abit special and are not included in base58 so we set it to 1.
+	// All other characters in "l33t" are valid.
+	std::transform(str.begin(), str.end(), str.begin(), [](char c){ return c == 'l' ? '1' : c; });
+
 	// Store the original string as the first in list.
 	list.push_back(str);
 
diff --git a/src/string.h b/src/string.h
index d006579..b3f6300 100644
--- a/src/string.h
+++ b/src/string.h
@@ -44,6 +44,6 @@ std::string& trim(std::string& str);
 std::string& base58_strip(std::string &str);
 strlist_t& base58_strip(strlist_t& list);
 
-strlist_t l33twords(const std::string& str);
+strlist_t l33twords(std::string str);
 
 #endif /* STRING_H */