diff --git a/spa/plugins/alsa/acp/acp.c b/spa/plugins/alsa/acp/acp.c
index c970361d9..b0b424dd0 100644
--- a/spa/plugins/alsa/acp/acp.c
+++ b/spa/plugins/alsa/acp/acp.c
@@ -94,9 +94,11 @@ static const uint32_t channel_table[PA_CHANNEL_POSITION_MAX] = {
 	[PA_CHANNEL_POSITION_TOP_REAR_CENTER] = ACP_CHANNEL_TRC,
 };
 
+#define ACP_N_ELEMENTS(arr)	(sizeof(arr) / sizeof((arr)[0]))
+
 static inline uint32_t channel_pa2acp(pa_channel_position_t channel)
 {
-	if (channel < 0 || (size_t)channel >= SPA_N_ELEMENTS(channel_table))
+	if (channel < 0 || (size_t)channel >= ACP_N_ELEMENTS(channel_table))
 		return ACP_CHANNEL_UNKNOWN;
 	return channel_table[channel];
 }
diff --git a/spa/plugins/alsa/acp/channelmap.h b/spa/plugins/alsa/acp/channelmap.h
index 9a2ec74a2..bb713b5d3 100644
--- a/spa/plugins/alsa/acp/channelmap.h
+++ b/spa/plugins/alsa/acp/channelmap.h
@@ -25,8 +25,6 @@
 extern "C" {
 #endif
 
-#include <spa/utils/defs.h>
-
 #define PA_CHANNELS_MAX	64
 
 #define PA_CHANNEL_MAP_SNPRINT_MAX 336
@@ -163,17 +161,17 @@ static inline pa_channel_map* pa_channel_map_init_auto(pa_channel_map *m, unsign
                 case 8:
                     m->map[6] = PA_CHANNEL_POSITION_SIDE_LEFT;
                     m->map[7] = PA_CHANNEL_POSITION_SIDE_RIGHT;
-                    SPA_FALLTHROUGH
+                    /* Fall through */
                 case 6:
                     m->map[5] = PA_CHANNEL_POSITION_LFE;
-                    SPA_FALLTHROUGH
+                    /* Fall through */
                 case 5:
                     m->map[4] = PA_CHANNEL_POSITION_FRONT_CENTER;
-                    SPA_FALLTHROUGH
+                    /* Fall through */
                 case 4:
                     m->map[2] = PA_CHANNEL_POSITION_REAR_LEFT;
                     m->map[3] = PA_CHANNEL_POSITION_REAR_RIGHT;
-                    SPA_FALLTHROUGH
+                    /* Fall through */
                 case 2:
                     m->map[0] = PA_CHANNEL_POSITION_FRONT_LEFT;
                     m->map[1] = PA_CHANNEL_POSITION_FRONT_RIGHT;