diff --git a/interpreter/cling/lib/Utils/AST.cpp b/interpreter/cling/lib/Utils/AST.cpp
index 4cd16d7ebdc24..15bef584677f0 100644
--- a/interpreter/cling/lib/Utils/AST.cpp
+++ b/interpreter/cling/lib/Utils/AST.cpp
@@ -1722,6 +1722,14 @@ namespace utils {
       }
       QT = etype_input->getNamedType();
     }
+
+    // We don't consider the alias introduced by `using a::X` as a new type.
+    // The qualified name is still a::X.
+    if (const auto* UT = QT->getAs<UsingType>()) {
+      QT = Ctx.getQualifiedType(UT->getUnderlyingType(), prefix_qualifiers);
+      return GetFullyQualifiedType(QT, Ctx);
+    }
+
     if (prefix == nullptr) {
       // Create a nested name specifier if needed (i.e. if the decl context
       // is not the global scope.
diff --git a/roottest/root/meta/naming/execResolveTypedef.cxx b/roottest/root/meta/naming/execResolveTypedef.cxx
index 772609171ce1d..1c6fc0885be36 100644
--- a/roottest/root/meta/naming/execResolveTypedef.cxx
+++ b/roottest/root/meta/naming/execResolveTypedef.cxx
@@ -225,7 +225,7 @@ int execResolveTypedef()
 
    testing("unsigned int", TClassEdit::ResolveTypedef("SG::sgkey_t"));
    testing("unsigned int", TClass::GetClass("PackedParameters")->GetDataMember("m_sgkey")->GetTrueTypeName());
-   testing("SG::sgkey_t", TClass::GetClass("PackedParameters")->GetDataMember("m_sgkey")->GetFullTypeName());
+   testing("uint32_t", TClass::GetClass("PackedParameters")->GetDataMember("m_sgkey")->GetFullTypeName());
    testing("RT::EX::ClusterSize", TClassEdit::ResolveTypedef("RT::EX::ClusterSize_t"));
    return 0;
 }
diff --git a/roottest/root/meta/naming/execResolveTypedef.ref b/roottest/root/meta/naming/execResolveTypedef.ref
index f1010a164e983..82bcf1edb400d 100644
--- a/roottest/root/meta/naming/execResolveTypedef.ref
+++ b/roottest/root/meta/naming/execResolveTypedef.ref
@@ -85,6 +85,6 @@ Test 82 The result is correct: ::SomeTypedefName_tSF
 Test 83 The result is correct: ::int
 Test 84 The result is correct: unsigned int
 Test 85 The result is correct: unsigned int
-Test 86 The result is correct: SG::sgkey_t
+Test 86 The result is correct: uint32_t
 Test 87 The result is correct: RT::EX::ClusterSize
 (int) 0