diff --git a/hls/assignment/sobel/sobel.cpp b/hls/assignment/sobel/sobel.cpp
index 3f3deb2..f9e0a1c 100644
--- a/hls/assignment/sobel/sobel.cpp
+++ b/hls/assignment/sobel/sobel.cpp
@@ -3,6 +3,11 @@
 
 void sobel(uint8_t *__restrict__ out, uint8_t *__restrict__ in, const int width, const int height)
 {
+#pragma HLS INTERFACE axis port=out bundle=boutput
+#pragma HLS INTERFACE axis port=in bundle=binput
+#pragma HLS INTERFACE s_axilite port=width bundle=bwidth
+#pragma HLS INTERFACE s_axilite port=height bundle=bheight
+
     const int sobelFilter[3][3] = {
         {-1, 0, 1}, 
         {-2, 0, 2},