diff --git a/libultraship/mixer.c b/libultraship/mixer.c
index 302a54ef477..1e66dc8a1d7 100644
--- a/libultraship/mixer.c
+++ b/libultraship/mixer.c
@@ -364,7 +364,7 @@ void aS8DecImpl(uint8_t flags, ADPCM_STATE state) {
     memcpy(state, out - 16, 16 * sizeof(int16_t));
 }
 
-void aAddMixerImpl(uint16_t in_addr, uint16_t out_addr, uint16_t count) {
+void aAddMixerImpl(uint16_t count, uint16_t in_addr, uint16_t out_addr) {
     int16_t *in = BUF_S16(in_addr);
     int16_t *out = BUF_S16(out_addr);
     int nbytes = ROUND_UP_64(ROUND_DOWN_16(count));
diff --git a/libultraship/mixer.h b/libultraship/mixer.h
index 62cf7e4ba19..2e1279a8633 100644
--- a/libultraship/mixer.h
+++ b/libultraship/mixer.h
@@ -51,7 +51,7 @@ void aEnvMixerImpl(uint16_t in_addr, uint16_t n_samples, bool swap_reverb,
                    int32_t wet_dry_addr, u32 unk);
 void aMixImpl(uint16_t count, int16_t gain, uint16_t in_addr, uint16_t out_addr);
 void aS8DecImpl(uint8_t flags, ADPCM_STATE state);
-void aAddMixerImpl(uint16_t in_addr, uint16_t out_addr, uint16_t count);
+void aAddMixerImpl(uint16_t count, uint16_t in_addr, uint16_t out_addr);
 void aDuplicateImpl(uint16_t count, uint16_t in_addr, uint16_t out_addr);
 void aResampleZohImpl(uint16_t pitch, uint16_t start_fract);
 void aInterlImpl(uint16_t in_addr, uint16_t out_addr, uint16_t n_samples);