diff --git a/spa/plugins/audioconvert/channelmix-ops.c b/spa/plugins/audioconvert/channelmix-ops.c
index 015d285ed..cabc556b8 100644
--- a/spa/plugins/audioconvert/channelmix-ops.c
+++ b/spa/plugins/audioconvert/channelmix-ops.c
@@ -776,7 +776,7 @@ int channelmix_init(struct channelmix *mix)
 	mix->func_name = info->name;
 
 	if (mix->hilbert_taps > 0) {
-		mix->n_taps = SPA_CLAMP(mix->hilbert_taps, 15u, 255u) | 1;
+		mix->n_taps = SPA_CLAMP(mix->hilbert_taps, 15u, MAX_TAPS) | 1;
 		blackman_window(mix->taps, mix->n_taps);
 		hilbert_generate(mix->taps, mix->n_taps);
 		reverse_taps(mix->taps, mix->n_taps);
diff --git a/spa/plugins/audioconvert/channelmix-ops.h b/spa/plugins/audioconvert/channelmix-ops.h
index dfc0bccde..4f6249c3c 100644
--- a/spa/plugins/audioconvert/channelmix-ops.h
+++ b/spa/plugins/audioconvert/channelmix-ops.h
@@ -24,7 +24,7 @@
 #define MASK_7_1	_M(FL)|_M(FR)|_M(FC)|_M(LFE)|_M(SL)|_M(SR)|_M(RL)|_M(RR)
 
 #define BUFFER_SIZE 4096
-#define MAX_TAPS 255
+#define MAX_TAPS 255u
 
 struct channelmix {
 	uint32_t src_chan;