diff --git a/qtools/qcstring.cpp b/qtools/qcstring.cpp
index fdd9971ac62..49bf8426b06 100644
--- a/qtools/qcstring.cpp
+++ b/qtools/qcstring.cpp
@@ -247,9 +247,9 @@ QCString QCString::right( uint len ) const
 
 QCString QCString::mid( uint index, uint len) const
 {
-  int slen = length();
+  uint slen = (uint)length();
   if (len==0xffffffff) len = slen-index;
-  if (isEmpty() || (int)index>=slen || len==0)
+  if (isEmpty() || index>=slen || len==0)
   {
     return QCString();
   }
diff --git a/src/doxygen.cpp b/src/doxygen.cpp
index f0a871943f5..b9437f61265 100644
--- a/src/doxygen.cpp
+++ b/src/doxygen.cpp
@@ -1010,6 +1010,7 @@ static Definition *buildScopeFromQualifiedName(const QCString name,
   while (i<level)
   {
     int idx=getScopeFragment(name,p,&l);
+    if (idx==-1) return prevScope;
     QCString nsName = name.mid(idx,l);
     if (nsName.isEmpty()) return prevScope;
     if (!fullScope.isEmpty()) fullScope+="::";