diff --git a/src/browser-entry.ts b/src/browser-entry.ts
index 89f2833..aaa1f0e 100644
--- a/src/browser-entry.ts
+++ b/src/browser-entry.ts
@@ -40,9 +40,9 @@ export { EdgeTTSBrowser } from './browser';
 // Export the new simplified browser-specific API as the main EdgeTTS
 export {
   BrowserEdgeTTS as EdgeTTS,
-  ProsodyOptions,
-  WordBoundary,
-  SynthesisResult,
+  type ProsodyOptions,
+  type WordBoundary,
+  type SynthesisResult,
   createVTT,
   createSRT
 } from './browser-simple';
@@ -50,7 +50,7 @@ export {
 // Export browser-specific implementations to avoid Node.js dependencies
 export {
   BrowserCommunicate as Communicate,
-  BrowserCommunicateOptions as CommunicateOptions
+  type BrowserCommunicateOptions as CommunicateOptions
 } from './browser-communicate';
 
 export {
@@ -66,4 +66,4 @@ export { SubMaker } from './submaker';
 
 // Common types and exceptions
 export * from './exceptions';
-export * from './types'; 
\ No newline at end of file
+export * from './types'; 
diff --git a/src/index.ts b/src/index.ts
index 323a927..4a2e51e 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -37,17 +37,25 @@
  */
 
 // Node.js-specific API (uses axios, Node.js crypto, etc.)
-export { Communicate, CommunicateOptions } from './communicate';
+export { Communicate, type CommunicateOptions } from './communicate';
 export { SubMaker } from './submaker';
 export { VoicesManager, listVoices } from './voices';
 
 // Simple API (works in both Node.js and browsers when using appropriate exports)
-export { EdgeTTS, ProsodyOptions, WordBoundary, SynthesisResult, createVTT, createSRT, UniversalEdgeTTS } from './simple';
+export {
+  EdgeTTS,
+  type ProsodyOptions,
+  type WordBoundary,
+  type SynthesisResult,
+  createVTT,
+  createSRT,
+  UniversalEdgeTTS
+} from './simple';
 
 // Universal/Isomorphic API (works in both Node.js and browsers)
 export {
   IsomorphicCommunicate,
-  IsomorphicCommunicateOptions
+  type IsomorphicCommunicateOptions
 } from './isomorphic-communicate';
 export {
   IsomorphicVoicesManager,
@@ -59,9 +67,9 @@ export { IsomorphicDRM } from './isomorphic-drm';
 // Simple isomorphic API
 export {
   IsomorphicEdgeTTS,
-  ProsodyOptions as IsomorphicProsodyOptions,
-  WordBoundary as IsomorphicWordBoundary,
-  SynthesisResult as IsomorphicSynthesisResult,
+  type ProsodyOptions as IsomorphicProsodyOptions,
+  type WordBoundary as IsomorphicWordBoundary,
+  type SynthesisResult as IsomorphicSynthesisResult,
   createVTT as createVTTIsomorphic,
   createSRT as createSRTIsomorphic
 } from './isomorphic-simple';
@@ -69,7 +77,7 @@ export {
 // Universal aliases (preferred naming)
 export {
   IsomorphicCommunicate as UniversalCommunicate,
-  IsomorphicCommunicateOptions as UniversalCommunicateOptions
+  type IsomorphicCommunicateOptions as UniversalCommunicateOptions
 } from './isomorphic-communicate';
 export {
   IsomorphicVoicesManager as UniversalVoicesManager,
@@ -79,9 +87,9 @@ export {
 export { IsomorphicDRM as UniversalDRM } from './isomorphic-drm';
 export {
   IsomorphicEdgeTTS as UniversalEdgeTTS_Isomorphic,
-  ProsodyOptions as UniversalProsodyOptions_Isomorphic,
-  WordBoundary as UniversalWordBoundary_Isomorphic,
-  SynthesisResult as UniversalSynthesisResult_Isomorphic,
+  type ProsodyOptions as UniversalProsodyOptions_Isomorphic,
+  type WordBoundary as UniversalWordBoundary_Isomorphic,
+  type SynthesisResult as UniversalSynthesisResult_Isomorphic,
   createVTT as createVTTUniversal_Isomorphic,
   createSRT as createSRTUniversal_Isomorphic
 } from './isomorphic-simple';
@@ -89,13 +97,13 @@ export {
 // Browser-specific API (uses native browser APIs only)
 export {
   EdgeTTSBrowser,
-  ProsodyOptions as BrowserProsodyOptions,
-  WordBoundary as BrowserWordBoundary,
-  SynthesisResult as BrowserSynthesisResult,
+  type ProsodyOptions as BrowserProsodyOptions,
+  type WordBoundary as BrowserWordBoundary,
+  type SynthesisResult as BrowserSynthesisResult,
   createVTT as createVTTBrowser,
   createSRT as createSRTBrowser
 } from './browser';
 
 // Common types and exceptions
 export * from './exceptions';
-export * from './types'; 
\ No newline at end of file
+export * from './types'; 
diff --git a/src/isomorphic-communicate.ts b/src/isomorphic-communicate.ts
index cef8b02..5a9bd8c 100644
--- a/src/isomorphic-communicate.ts
+++ b/src/isomorphic-communicate.ts
@@ -417,4 +417,4 @@ export class IsomorphicCommunicate {
       }
     }
   }
-} 
\ No newline at end of file
+} 
diff --git a/src/isomorphic-entry.ts b/src/isomorphic-entry.ts
index beb368b..d667e8c 100644
--- a/src/isomorphic-entry.ts
+++ b/src/isomorphic-entry.ts
@@ -31,7 +31,7 @@
 
 export {
   IsomorphicCommunicate as Communicate,
-  IsomorphicCommunicateOptions as CommunicateOptions
+  type IsomorphicCommunicateOptions as CommunicateOptions
 } from './isomorphic-communicate';
 
 export {
@@ -45,9 +45,9 @@ export { IsomorphicDRM as DRM } from './isomorphic-drm';
 // Simple API using isomorphic backend (all from isomorphic-simple to avoid Node.js deps)
 export {
   IsomorphicEdgeTTS as EdgeTTS,
-  ProsodyOptions,
-  WordBoundary,
-  SynthesisResult,
+  type ProsodyOptions,
+  type WordBoundary,
+  type SynthesisResult,
   createVTT,
   createSRT
 } from './isomorphic-simple';
@@ -62,7 +62,7 @@ export * from './types';
 // Universal aliases (preferred naming convention)
 export {
   IsomorphicCommunicate as UniversalCommunicate,
-  IsomorphicCommunicateOptions as UniversalCommunicateOptions
+  type IsomorphicCommunicateOptions as UniversalCommunicateOptions
 } from './isomorphic-communicate';
 
 export {
@@ -75,4 +75,4 @@ export { IsomorphicDRM as UniversalDRM } from './isomorphic-drm';
 
 export {
   IsomorphicEdgeTTS as UniversalEdgeTTS
-} from './isomorphic-simple'; 
\ No newline at end of file
+} from './isomorphic-simple'; 
diff --git a/src/webworker-entry.ts b/src/webworker-entry.ts
index 96d3b0b..fc5e2dd 100644
--- a/src/webworker-entry.ts
+++ b/src/webworker-entry.ts
@@ -41,7 +41,7 @@
 
 export {
   IsomorphicCommunicate as Communicate,
-  IsomorphicCommunicateOptions as CommunicateOptions
+  type IsomorphicCommunicateOptions as CommunicateOptions
 } from './isomorphic-communicate';
 
 export {
@@ -56,9 +56,9 @@ export { IsomorphicDRM as DRM } from './isomorphic-drm';
 // Import everything from isomorphic-simple to avoid Node.js dependencies
 export {
   IsomorphicEdgeTTS as EdgeTTS,
-  ProsodyOptions,
-  WordBoundary,
-  SynthesisResult,
+  type ProsodyOptions,
+  type WordBoundary,
+  type SynthesisResult,
   createVTT,
   createSRT
 } from './isomorphic-simple';
@@ -101,4 +101,4 @@ export function postAudioMessage(audio: Blob, subtitle: any[]) {
   } else {
     console.warn('postAudioMessage should only be called in Web Worker context');
   }
-} 
\ No newline at end of file
+}