diff --git a/third_party/nestegg/README.webm b/third_party/nestegg/README.webm
index 4cf2e4d220b2b3a8c610cce1f75f072e5cdffa42..8e3760bd72c42f4074de27efad6446853ba24e33 100644
--- a/third_party/nestegg/README.webm
+++ b/third_party/nestegg/README.webm
@@ -21,3 +21,4 @@ nestegg.c|975 col 6| warning: ‘r’ may be used uninitialized in this function
 - ne_read_(string|binary|block): normalize size_t usage
 - ne_parse: normalize size_t usage
 - quiet read related uint64->size_t warnings
+- ne_buffer_read: quiet uint64->size_t warning
diff --git a/third_party/nestegg/src/nestegg.c b/third_party/nestegg/src/nestegg.c
index 124b98b3e52460b9082795e3968914d18995225c..c7e2b024a09e2e8ea0676ac4ddcef961d4203ac0 100644
--- a/third_party/nestegg/src/nestegg.c
+++ b/third_party/nestegg/src/nestegg.c
@@ -1605,7 +1605,7 @@ ne_buffer_read(void * buffer, size_t length, void * user_data)
   struct sniff_buffer * sb = user_data;
 
   int rv = 1;
-  size_t available = sb->length - sb->offset;
+  size_t available = sb->length - (size_t)sb->offset;
 
   if (available < length)
     return 0;