diff --git a/Makefile b/Makefile
index ff8e0327..ca7dc49d 100644
--- a/Makefile
+++ b/Makefile
@@ -200,6 +200,9 @@ tools/textfilter: tools/textfilter.c
 .s.o:
 	$(CC) $(CFLAGS) -c $< -o $@
 
+.S.o:
+	$(CC) $(CFLAGS) -c $< -o $@
+
 # special flags - perhaps fix this someday instead?
 pico/draw.o: CFLAGS += -fno-strict-aliasing
 pico/draw2.o: CFLAGS += -fno-strict-aliasing
diff --git a/pico/sound/mix_arm.s b/pico/sound/mix_arm.S
similarity index 99%
rename from pico/sound/mix_arm.s
rename to pico/sound/mix_arm.S
index 60a09495..5088e61b 100644
--- a/pico/sound/mix_arm.s
+++ b/pico/sound/mix_arm.S
@@ -299,6 +299,7 @@ m32_16_mo_no_unal2:
     bx      lr
 
 
+#ifdef __GP2X__
 
 .data
 .align 4
@@ -366,4 +367,6 @@ m32_16l_st_l_no_unal2:
     ldmfd   sp!, {r4-r9,lr}
     bx      lr
 
+#endif /* __GP2X__ */
+
 @ vim:filetype=armasm
diff --git a/platform/common/common.mak b/platform/common/common.mak
index 0cf8a7e4..f89d7920 100644
--- a/platform/common/common.mak
+++ b/platform/common/common.mak
@@ -69,7 +69,7 @@ DEFINES += _ASM_32X_DRAW
 SRCS_COMMON += $(R)pico/32x/draw_arm.s
 endif
 ifeq "$(asm_mix)" "1"
-SRCS_COMMON += $(R)pico/sound/mix_arm.s
+SRCS_COMMON += $(R)pico/sound/mix_arm.S
 endif
 endif # ARCH=arm