diff --git a/include/crc_util.h b/include/crc_util.h
index 6eae8e2..3dfe9c2 100644
--- a/include/crc_util.h
+++ b/include/crc_util.h
@@ -1,7 +1,16 @@
 #include <stdio.h>
 
 // PNG File Struct
-struct PNG
+struct PNG_FILE_STRUCT {
+	unsigned char file_sig[8];
+	int file_width;
+	int file_height;
+	int bit_depth;
+	int color_type;
+	int compression_method;
+	int filter_method;
+	int interlace_method;
+};
 
 extern const long png_signature[8];