diff --git a/include/hexagram/pcapng.h b/include/hexagram/pcapng.h
index 4bec588..354a9a3 100644
--- a/include/hexagram/pcapng.h
+++ b/include/hexagram/pcapng.h
@@ -7,7 +7,8 @@ enum {
     HEXAGRAM_PCAPNG_ERROR_OK        = 0,
     HEXAGRAM_PCAPNG_ERROR_IO        = 1,
     HEXAGRAM_PCAPNG_ERROR_TRUNCATED = 2,
-    HEXAGRAM_PCAPNG_ERROR_HANDLER   = 3
+    HEXAGRAM_PCAPNG_ERROR_FORMAT    = 3,
+    HEXAGRAM_PCAPNG_ERROR_HANDLER   = 4
 } hexagram_pcapng_error;
 
 typedef struct _hexagram_pcapng_header {
diff --git a/src/pcapng.c b/src/pcapng.c
index 4e628a8..505b42c 100644
--- a/src/pcapng.c
+++ b/src/pcapng.c
@@ -32,7 +32,7 @@ ssize_t hexagram_pcapng_stream_read(fd, handler, error)
 
         total += readlen;
 
-        if (handler(fd, header.type, header.length) < 0) {
+        if (handler(fd, header.type, header.length - sizeof(header) - sizeof(footer)) < 0) {
             *error = HEXAGRAM_PCAPNG_ERROR_HANDLER;
 
             goto error_io;
@@ -49,6 +49,12 @@ ssize_t hexagram_pcapng_stream_read(fd, handler, error)
 
             goto error_io;
         }
+
+        if (footer.length != header.length) {
+            *error = HEXAGRAM_PCAPNG_ERROR_FORMAT;
+
+            goto error_io;
+        }
     }
 
     *error = HEXAGRAM_PCAPNG_ERROR_OK;