diff --git a/ethertype-dump.c b/ethertype-dump.c
index 402e5a9..3c3280e 100644
--- a/ethertype-dump.c
+++ b/ethertype-dump.c
@@ -104,6 +104,7 @@ int main(int argc, char **argv) {
 		if (frame_length == -1) {
 			err(1, "recv");
 		}
+		size_t frame_data_length = frame_length <= 1522 ? frame_length : 1522;
 
 		if (frame_length < 64) {
 			errno = 0;
@@ -114,7 +115,7 @@ int main(int argc, char **argv) {
 		}
 
 		// Compute the CRC32 of the frame
-		uint32_t crc32_residue = crc32(frame, frame_length);
+		uint32_t crc32_residue = crc32(frame, frame_data_length);
 
 		if (crc32_residue != 0xc704dd7b) {
 			errno = 0;