diff --git a/Analysis/src/Frontend.cpp b/Analysis/src/Frontend.cpp
index 710e3699..125f2457 100644
--- a/Analysis/src/Frontend.cpp
+++ b/Analysis/src/Frontend.cpp
@@ -38,6 +38,7 @@ LUAU_FASTFLAGVARIABLE(DebugLuauLogSolverToJson, false)
 LUAU_FASTFLAGVARIABLE(DebugLuauReadWriteProperties, false)
 LUAU_FASTFLAGVARIABLE(LuauTypecheckLimitControls, false)
 LUAU_FASTFLAGVARIABLE(CorrectEarlyReturnInMarkDirty, false)
+LUAU_FASTFLAGVARIABLE(LuauDefinitionFileSetModuleName, false)
 
 namespace Luau
 {
@@ -165,6 +166,11 @@ LoadDefinitionFileResult Frontend::loadDefinitionFile(GlobalTypes& globals, Scop
     LUAU_TIMETRACE_SCOPE("loadDefinitionFile", "Frontend");
 
     Luau::SourceModule sourceModule;
+    if (FFlag::LuauDefinitionFileSetModuleName)
+    {
+        sourceModule.name = packageName;
+        sourceModule.humanReadableName = packageName;
+    }
     Luau::ParseResult parseResult = parseSourceForModule(source, sourceModule, captureComments);
     if (parseResult.errors.size() > 0)
         return LoadDefinitionFileResult{false, parseResult, sourceModule, nullptr};
diff --git a/tests/TypeInfer.definitions.test.cpp b/tests/TypeInfer.definitions.test.cpp
index 86f619fd..30153280 100644
--- a/tests/TypeInfer.definitions.test.cpp
+++ b/tests/TypeInfer.definitions.test.cpp
@@ -441,4 +441,27 @@ TEST_CASE_FIXTURE(Fixture, "class_definitions_reference_other_classes")
     REQUIRE(result.success);
 }
 
+TEST_CASE_FIXTURE(Fixture, "definition_file_has_source_module_name_set")
+{
+    ScopedFastFlag sff{"LuauDefinitionFileSetModuleName", true};
+
+    LoadDefinitionFileResult result = loadDefinition(R"(
+        declare class Foo
+        end
+    )");
+
+    REQUIRE(result.success);
+
+    CHECK_EQ(result.sourceModule.name, "@test");
+    CHECK_EQ(result.sourceModule.humanReadableName, "@test");
+
+    std::optional<TypeFun> fooTy = frontend.globals.globalScope->lookupType("Foo");
+    REQUIRE(fooTy);
+
+    const ClassType* ctv = get<ClassType>(fooTy->type);
+
+    REQUIRE(ctv);
+    CHECK_EQ(ctv->definitionModuleName, "@test");
+}
+
 TEST_SUITE_END();