diff --git a/src/ifcparse/IfcCharacterDecoder.cpp b/src/ifcparse/IfcCharacterDecoder.cpp
index dbb022c6e1..d1ecab9484 100644
--- a/src/ifcparse/IfcCharacterDecoder.cpp
+++ b/src/ifcparse/IfcCharacterDecoder.cpp
@@ -327,7 +327,7 @@ IfcCharacterEncoder::operator std::string() {
 	UChar32 ch;
 
 	const char* source = str.c_str();
-	const char* limit = source + str.size();
+	const char* limit = &*str.end();
 	
 	bool in_extended = false;
 
@@ -364,4 +364,4 @@ IfcCharacterEncoder::operator std::string() {
 #ifdef HAVE_ICU
 UErrorCode IfcCharacterEncoder::status = U_ZERO_ERROR;
 UConverter* IfcCharacterEncoder::converter = 0;
-#endif
+#endif
\ No newline at end of file