diff --git a/src/libs/cplusplus/CheckUndefinedSymbols.cpp b/src/libs/cplusplus/CheckUndefinedSymbols.cpp
index 3e435077a60cf806126312e25b4c6acc0b863832..98cf2226c25c0b52297b409e136721b181e7a9d2 100644
--- a/src/libs/cplusplus/CheckUndefinedSymbols.cpp
+++ b/src/libs/cplusplus/CheckUndefinedSymbols.cpp
@@ -255,6 +255,14 @@ bool CheckUndefinedSymbols::visit(TypeofSpecifierAST *)
     return false;
 }
 
+bool CheckUndefinedSymbols::visit(NamespaceAliasDefinitionAST *ast)
+{
+    if (const Identifier *id = identifier(ast->namespace_name_token))
+        _types.insert(QByteArray(id->chars(), id->size()));
+
+    return true;
+}
+
 bool CheckUndefinedSymbols::visit(NamedTypeSpecifierAST *ast)
 {
     if (ast->name) {
diff --git a/src/libs/cplusplus/CheckUndefinedSymbols.h b/src/libs/cplusplus/CheckUndefinedSymbols.h
index 06b41c8a127b5a453980d8adbaddd3e42d341896..00b8d4d1d7b929db086ee81d450010f855b735af 100644
--- a/src/libs/cplusplus/CheckUndefinedSymbols.h
+++ b/src/libs/cplusplus/CheckUndefinedSymbols.h
@@ -93,6 +93,7 @@ protected:
     virtual bool visit(QualifiedNameAST *ast);
     virtual bool visit(CastExpressionAST *ast);
     virtual bool visit(SizeofExpressionAST *ast);
+    virtual bool visit(NamespaceAliasDefinitionAST *ast);
 
     virtual bool visit(ObjCClassDeclarationAST *ast);
     virtual bool visit(ObjCProtocolRefsAST *ast);