diff --git a/libavcodec/ttaenc.c b/libavcodec/ttaenc.c
index 3cc54d78c5..08a0d0483a 100644
--- a/libavcodec/ttaenc.c
+++ b/libavcodec/ttaenc.c
@@ -164,7 +164,7 @@ pkt_alloc:
                     put_bits(&pb, 31, 0x7FFFFFFF);
                     unary -= 31;
                 } else {
-                    put_bits(&pb, unary, (1 << unary) - 1);
+                    put_bits(&pb, unary, (1U << unary) - 1);
                     unary = 0;
                 }
             } while (unary);