diff --git a/libretro/Makefile.common b/libretro/Makefile.common
index c869e78d..3025492b 100644
--- a/libretro/Makefile.common
+++ b/libretro/Makefile.common
@@ -46,5 +46,4 @@ SOURCES_CXX := $(CORE_DIR)/apu/apu.cpp \
 				 $(CORE_DIR)/spc7110.cpp \
 				 $(CORE_DIR)/srtc.cpp \
 				 $(CORE_DIR)/tile.cpp \
-                                 $(CORE_DIR)/msu1.cpp \
 				 $(CORE_DIR)/libretro/libretro.cpp
diff --git a/msu1.cpp b/msu1.cpp
index 1aa01d88..8c5f0bc7 100644
--- a/msu1.cpp
+++ b/msu1.cpp
@@ -196,6 +196,8 @@
 #include <fstream>
 #include <cerrno>
 
+#define APU_DEFAULT_INPUT_RATE		32000
+
 std::ifstream dataFile, audioFile;
 uint32 audioLoopPos;
 uint32 partial_samples;