diff --git a/src/conversions.cpp b/src/conversions.cpp
index 9d6ae3d..63c8d5f 100644
--- a/src/conversions.cpp
+++ b/src/conversions.cpp
@@ -80,7 +80,7 @@ ncnn::Mat avframe_to_ncnn_mat(AVFrame *frame) {
     // Allocate a new ncnn::Mat and copy the data
     int width = converted_frame->width;
     int height = converted_frame->height;
-    ncnn::Mat ncnn_image = ncnn::Mat(width, height, 3, 3);  // BGR has 3 channels
+    ncnn::Mat ncnn_image = ncnn::Mat(width, height, static_cast<size_t>(3), 3);
 
     // Manually copy the pixel data from AVFrame to the new ncnn::Mat
     const uint8_t *src_data = converted_frame->data[0];
diff --git a/src/realesrgan_filter.cpp b/src/realesrgan_filter.cpp
index 44eb477..419e571 100644
--- a/src/realesrgan_filter.cpp
+++ b/src/realesrgan_filter.cpp
@@ -113,7 +113,7 @@ int RealesrganFilter::process_frame(AVFrame *in_frame, AVFrame **out_frame) {
     // Allocate space for ouptut ncnn::Mat
     int output_width = in_mat.w * realesrgan->scale;
     int output_height = in_mat.h * realesrgan->scale;
-    ncnn::Mat out_mat = ncnn::Mat(output_width, output_height, 3, 3);
+    ncnn::Mat out_mat = ncnn::Mat(output_width, output_height, static_cast<size_t>(3), 3);
 
     ret = realesrgan->process(in_mat, out_mat);
     if (ret != 0) {