diff --git a/src/qmlcompiler/qqmljsfunctioninitializer.cpp b/src/qmlcompiler/qqmljsfunctioninitializer.cpp
index 0139071cc0..8cd3bb3536 100644
--- a/src/qmlcompiler/qqmljsfunctioninitializer.cpp
+++ b/src/qmlcompiler/qqmljsfunctioninitializer.cpp
@@ -94,10 +94,12 @@ void QQmlJSFunctionInitializer::populateSignature(
                 if (const auto type = m_typeResolver->typeFromAST(argument.typeAnnotation->type)) {
                     function->argumentTypes.append(type);
                 } else {
+                    function->argumentTypes.append(m_typeResolver->varType());
                     signatureError(u"Cannot resolve the argument type %1."_qs
                                    .arg(argument.typeAnnotation->type->toString()));
                 }
             } else {
+                function->argumentTypes.append(m_typeResolver->varType());
                 signatureError(u"Functions without type annotations won't be compiled"_qs);
             }
         }
diff --git a/tests/auto/qml/qmllint/data/unknownTypeInRegister.qml b/tests/auto/qml/qmllint/data/unknownTypeInRegister.qml
new file mode 100644
index 0000000000..72902d292b
--- /dev/null
+++ b/tests/auto/qml/qmllint/data/unknownTypeInRegister.qml
@@ -0,0 +1,7 @@
+import QtQuick
+
+ListModel {
+    function foo(index) {
+        move(index, 1, 1);
+    }
+}
diff --git a/tests/auto/qml/qmllint/tst_qmllint.cpp b/tests/auto/qml/qmllint/tst_qmllint.cpp
index 5da838c299..b8fcdc49f3 100644
--- a/tests/auto/qml/qmllint/tst_qmllint.cpp
+++ b/tests/auto/qml/qmllint/tst_qmllint.cpp
@@ -90,6 +90,7 @@ private Q_SLOTS:
     void absolutePath();
     void multiGrouped();
     void javascriptVariableArgs();
+    void unknownTypeInRegister();
 
 private:
     enum DefaultIncludeOption { NoDefaultIncludes, UseDefaultIncludes };
@@ -1266,5 +1267,12 @@ void TestQmllint::javascriptVariableArgs()
             .contains(QStringLiteral("Function expects 0 arguments, but 2 were provided")));
 }
 
+void TestQmllint::unknownTypeInRegister()
+{
+    QVERIFY(runQmllint("unknownTypeInRegister.qml", false, { "--compiler", "warning" })
+                    .contains(QStringLiteral(
+                            "Functions without type annotations won't be compiled")));
+}
+
 QTEST_MAIN(TestQmllint)
 #include "tst_qmllint.moc"