diff --git a/.gitignore b/.gitignore
index 58a63eb872..3d5bfe3e55 100644
--- a/.gitignore
+++ b/.gitignore
@@ -7,4 +7,6 @@ packages/*/*.tgz
 packages/*/docs
 package-lock.json
 *.log
-.env
\ No newline at end of file
+.env
+# bun.lock
+playground/
diff --git a/packages/core/src/transformers/MethodTransformer.ts b/packages/core/src/transformers/MethodTransformer.ts
index 8f8c363b5f..7affff5a86 100644
--- a/packages/core/src/transformers/MethodTransformer.ts
+++ b/packages/core/src/transformers/MethodTransformer.ts
@@ -78,20 +78,22 @@ const get_escaped_type =
 const escape_promise =
   (checker: ts.TypeChecker) =>
   (type: ts.Type): ts.Type => {
-    const generic: readonly ts.Type[] = checker.getTypeArguments(
-      type as ts.TypeReference,
-    );
-    if (generic.length !== 1)
-      throw new Error(
-        "Error on ImportAnalyzer.analyze(): invalid promise type.",
+    try {
+      const generic: readonly ts.Type[] = checker.getTypeArguments(
+        type as ts.TypeReference,
       );
-    return generic[0]!;
+      if (!generic?.length) return type;
+      return generic[0] ?? type;
+    } catch {
+      return type;
+    }
   };
 
-const get_name = (symbol: ts.Symbol): string =>
-  explore_name(symbol.getDeclarations()![0]!.parent)(
-    symbol.escapedName.toString(),
-  );
+const get_name = (symbol: ts.Symbol): string => {
+  const parent: ts.Node | undefined = symbol.getDeclarations()?.[0]?.parent;
+  const name: string = symbol.escapedName?.toString() ?? "";
+  return parent ? explore_name(parent)(name) : name;
+};
 
 const explore_name =
   (decl: ts.Node) =>
diff --git a/tests/test-sdk/.gitignore b/tests/test-sdk/.gitignore
index a562634892..bd7b71cec5 100644
--- a/tests/test-sdk/.gitignore
+++ b/tests/test-sdk/.gitignore
@@ -6,6 +6,7 @@ features/*/src/test/features/api/automated
 
 features/clone*/src/api/structures
 features/clone-type-create-duplicate/sdk
+features/method-transformer-defensive/src/api/structures
 features/configurations/src/api/bbs
 features/configurations/src/api/common
 features/configurations/*.swagger.json
\ No newline at end of file
diff --git a/tests/test-sdk/features/method-transformer-defensive/nestia.config.ts b/tests/test-sdk/features/method-transformer-defensive/nestia.config.ts
new file mode 100644
index 0000000000..f75934d1f7
--- /dev/null
+++ b/tests/test-sdk/features/method-transformer-defensive/nestia.config.ts
@@ -0,0 +1,11 @@
+import { INestiaConfig } from "@nestia/sdk";
+
+export const NESTIA_CONFIG: INestiaConfig = {
+  input: ["src/controllers"],
+  output: "src/api",
+  clone: true,
+  swagger: {
+    output: "swagger.json",
+  },
+};
+export default NESTIA_CONFIG;
diff --git a/tests/test-sdk/features/method-transformer-defensive/src/controllers/ImportTypeController.ts b/tests/test-sdk/features/method-transformer-defensive/src/controllers/ImportTypeController.ts
new file mode 100644
index 0000000000..3ebf7739f1
--- /dev/null
+++ b/tests/test-sdk/features/method-transformer-defensive/src/controllers/ImportTypeController.ts
@@ -0,0 +1,35 @@
+import { TypedRoute } from "@nestia/core";
+import { Controller } from "@nestjs/common";
+
+@Controller("import-type")
+export class ImportTypeController {
+  @TypedRoute.Get("envelope")
+  public envelope(): IEnvelope<IGreeting> {
+    return { message: "ok", data: { greeting: "hello" } };
+  }
+
+  @TypedRoute.Get("alias")
+  public alias(): AliasEnvelope<IGreeting> {
+    return { message: "ok", data: { greeting: "hello" } };
+  }
+
+  @TypedRoute.Get<
+    import("./ImportTypeController").IEnvelope<
+      import("./ImportTypeController").IGreeting
+    >
+  >("decorator-generic")
+  public decoratorGeneric(): AliasEnvelope<IGreeting> {
+    return { message: "ok", data: { greeting: "hello" } };
+  }
+}
+
+export interface IEnvelope<T> {
+  message: string;
+  data: T | null;
+}
+
+export interface IGreeting {
+  greeting: string;
+}
+
+type AliasEnvelope<T> = IEnvelope<T>;
diff --git a/tests/test-sdk/features/method-transformer-defensive/src/controllers/InlineReturnController.ts b/tests/test-sdk/features/method-transformer-defensive/src/controllers/InlineReturnController.ts
new file mode 100644
index 0000000000..94256a1159
--- /dev/null
+++ b/tests/test-sdk/features/method-transformer-defensive/src/controllers/InlineReturnController.ts
@@ -0,0 +1,42 @@
+import { TypedRoute } from "@nestia/core";
+import { Controller } from "@nestjs/common";
+
+@Controller("inline-return")
+export class InlineReturnController {
+  @TypedRoute.Get("anonymous")
+  public anonymous(): Promise<{ foo: string; bar?: number }> {
+    return Promise.resolve({ foo: "ok" });
+  }
+
+  @TypedRoute.Get("intersection")
+  public intersection(): Promise<IWithX & IWithY> {
+    return Promise.resolve({ x: 1, y: "hi" });
+  }
+
+  @TypedRoute.Get("return-type")
+  public returnType(): Promise<ReturnType<typeof getItem>> {
+    return Promise.resolve(getItem());
+  }
+
+  @TypedRoute.Get("inferred")
+  public inferred(): Promise<InferReturn<() => IItem>> {
+    return Promise.resolve({ id: 1, label: "item" });
+  }
+}
+
+interface IWithX {
+  x: number;
+}
+interface IWithY {
+  y: string;
+}
+interface IItem {
+  id: number;
+  label: string;
+}
+
+type InferReturn<T> = T extends (...args: any[]) => infer R ? R : never;
+
+function getItem(): IItem {
+  return { id: 1, label: "item" };
+}
diff --git a/tests/test-sdk/features/method-transformer-defensive/tsconfig.json b/tests/test-sdk/features/method-transformer-defensive/tsconfig.json
new file mode 100644
index 0000000000..ccd8aec38c
--- /dev/null
+++ b/tests/test-sdk/features/method-transformer-defensive/tsconfig.json
@@ -0,0 +1,10 @@
+{
+  "extends": "../../config/tsconfig.json",
+  "compilerOptions": {
+    "paths": {
+      "@api": ["./src/api"],
+      "@api/lib/*": ["./src/api/*"],
+    },
+  },
+  "include": ["src"],
+}