diff --git a/dist/apiMessage.js b/dist/apiMessage.js
index 0cc9cac..9e823e4 100644
--- a/dist/apiMessage.js
+++ b/dist/apiMessage.js
@@ -62,16 +62,16 @@ function parseSendMessageOption(o) {
     if (typeof o.messageType !== "number") {
         throwError(Errors.InvokeFailed, `Expected messageType is number, but get ${o.messageType}.`);
     }
-    if (typeof o.messageThumb !== undefined) {
+    if (o.messageThumb !== undefined) {
         option.messageThumb = resolveImage(o.messageThumb);
     }
     // @ts-ignore
-    if (typeof o.image !== undefined) {
+    if (o.image !== undefined) {
         // @ts-ignore
         option.image = resolveImage(o.image);
     }
     // @ts-ignore
-    if (typeof o.hdImage !== undefined) {
+    if (o.hdImage !== undefined) {
         // @ts-ignore
         option.hdImage = resolveImage(o.hdImage);
     }
@@ -113,12 +113,12 @@ function parseSendMessageRespOption(o) {
         throwError(Errors.InvokeFailed, `Expected messageType is number, but get ${o.messageType}.`);
     }
     // @ts-ignore
-    if (typeof o.image !== undefined) {
+    if (o.image !== undefined) {
         // @ts-ignore
         option.image = resolveImage(o.image);
     }
     // @ts-ignore
-    if (typeof o.hdImage !== undefined) {
+    if (o.hdImage !== undefined) {
         // @ts-ignore
         option.hdImage = resolveImage(o.hdImage);
     }
diff --git a/src/apiMessage.ts b/src/apiMessage.ts
index 017210a..c66eb01 100644
--- a/src/apiMessage.ts
+++ b/src/apiMessage.ts
@@ -153,18 +153,18 @@ function parseSendMessageOption(o: ISendMessageOption) {
             `Expected messageType is number, but get ${o.messageType}.`);
     }
 
-    if (typeof o.messageThumb !== undefined) {
+    if (o.messageThumb !== undefined) {
         option.messageThumb = resolveImage(o.messageThumb as string);
     }
 
     // @ts-ignore
-    if (typeof o.image !== undefined) {
+    if (o.image !== undefined) {
         // @ts-ignore
         option.image = resolveImage(o.image);
     }
 
     // @ts-ignore
-    if (typeof o.hdImage !== undefined) {
+    if (o.hdImage !== undefined) {
         // @ts-ignore
         option.hdImage = resolveImage(o.hdImage);
     }
@@ -237,13 +237,13 @@ function parseSendMessageRespOption(o: ISendMessageRespOption) {
     }
 
     // @ts-ignore
-    if (typeof o.image !== undefined) {
+    if (o.image !== undefined) {
         // @ts-ignore
         option.image = resolveImage(o.image);
     }
 
     // @ts-ignore
-    if (typeof o.hdImage !== undefined) {
+    if (o.hdImage !== undefined) {
         // @ts-ignore
         option.hdImage = resolveImage(o.hdImage);
     }