diff --git a/libavcodec/jpeg2000dec.c b/libavcodec/jpeg2000dec.c
index e1da04d0c6..8df6ee2df4 100644
--- a/libavcodec/jpeg2000dec.c
+++ b/libavcodec/jpeg2000dec.c
@@ -198,7 +198,7 @@ static int get_siz(Jpeg2000DecoderContext *s)
         uint8_t x    = bytestream2_get_byteu(&s->g);
         s->cbps[i]   = (x & 0x7f) + 1;
         s->precision = FFMAX(s->cbps[i], s->precision);
-        s->sgnd[i]   = (x & 0x80) == 1;
+        s->sgnd[i]   = !!(x & 0x80);
         s->cdx[i]    = bytestream2_get_byteu(&s->g);
         s->cdy[i]    = bytestream2_get_byteu(&s->g);