diff --git a/zsnes/src/makefile.dos b/zsnes/src/makefile.dos
index 3975f8d5..4b607513 100644
--- a/zsnes/src/makefile.dos
+++ b/zsnes/src/makefile.dos
@@ -77,6 +77,8 @@ PP=gpp
 %.o: %.asm
 	${ASM} ${ASMFLAGS} -o $@ $<
 
+chips/dsp1emu.o: chips/dsp1emu.c
+	${CC} -O2 ${CFLAGS} -o $@ -c $<
 
 ALL: zsnes.exe
 
diff --git a/zsnes/src/makefile.win b/zsnes/src/makefile.win
index a1e2b094..5bfa6d1a 100644
--- a/zsnes/src/makefile.win
+++ b/zsnes/src/makefile.win
@@ -85,6 +85,8 @@ CC=cl
 %.obj: %.asm
 	${ASM} ${ASMFLAGS} -o $@ $<
 
+chips/dsp1emu.obj : chips/dsp1emu.c
+	${CC} /O2t ${CFLAGS} /Fo$@ $<
 
 ALL: zsnesw.exe