diff --git a/src/libImaging/BcnEncode.c b/src/libImaging/BcnEncode.c
index f6445d653..7a5072dde 100644
--- a/src/libImaging/BcnEncode.c
+++ b/src/libImaging/BcnEncode.c
@@ -258,7 +258,8 @@ ImagingBcnEncode(Imaging im, ImagingCodecState state, UINT8 *buf, int bytes) {
     UINT8 *dst = buf;
 
     for (;;) {
-        if (dst + 8 >= bytes + buf) {
+        // Loop writes a max of 16 bytes per iteration
+        if (dst + 16 >= bytes + buf) {
             break;
         }
         if (n == 5) {