diff --git a/ai/asr/keyword_spotting/kws_manager.h b/ai/asr/keyword_spotting/kws_manager.h
index 17c9b897f26d9cf71ed71947eacd75a084fa39d4..0746247fb9a3cffa22139e3f8f6ec29ded510da2 100644
--- a/ai/asr/keyword_spotting/kws_manager.h
+++ b/ai/asr/keyword_spotting/kws_manager.h
@@ -40,7 +40,7 @@ const std::vector<std::string> WORD_CONTENT = {
     "Unknown"
 };
 
-enum KwsStatus {
+enum KwsStatus : int {
     IDLE = 1000,
     PREPARED,
     RUNNING,
diff --git a/ai/cv/image_classification/picture_utils.cpp b/ai/cv/image_classification/picture_utils.cpp
index c6b222c0c83a47ee231388c97f5056662f8ef748..36af8d00a80ec2c1ed76cbb3f38c5c7b0e30309e 100644
--- a/ai/cv/image_classification/picture_utils.cpp
+++ b/ai/cv/image_classification/picture_utils.cpp
@@ -59,7 +59,7 @@ int WriteJpegFile(const string &filename, int quality,
     }
     jpeg_finish_compress(&cinfo);
 
-    fclose(outfile);
+    (void)fclose(outfile);
     jpeg_destroy_compress(&cinfo);
     return IC_RETCODE_SUCCESS;
 }
@@ -135,7 +135,7 @@ uint8_t *ReadJpegFile(const string &filename, int &srcWidth, int &srcHeight)
 
     (void)jpeg_finish_decompress(&cinfo);
     jpeg_destroy_decompress(&cinfo);
-    fclose(infile);
+    (void)fclose(infile);
     return buffer;
 }
 
diff --git a/ai/cv/image_classification/picture_utils.h b/ai/cv/image_classification/picture_utils.h
index dad7381de71d09168831cbb4887f3d1d1d899f56..927701d71e596e4e700bfa82e6a91e1d32bcff8b 100644
--- a/ai/cv/image_classification/picture_utils.h
+++ b/ai/cv/image_classification/picture_utils.h
@@ -32,14 +32,14 @@ struct MyErrorMgr {
 using MyErrorPtr = MyErrorMgr *;
 
 // The index order of BGR format
-enum BgrIndex {
+enum BgrIndex : int {
     BGR_BLUE = 0,
     BGR_GREEN,
     BGR_RED,
 };
 
 // The index order of RGB format
-enum RgbIndex {
+enum RgbIndex : int {
     RGB_RED = 0,
     RGB_GREEN,
     RGB_BLUE,