diff --git a/src/libFLAC/Makefile.am b/src/libFLAC/Makefile.am
index 50bceaeb..1075b0a0 100644
--- a/src/libFLAC/Makefile.am
+++ b/src/libFLAC/Makefile.am
@@ -11,6 +11,7 @@ endif
 
 libFLAC_la_SOURCES = \
 	bitbuffer.c \
+	bitmath.c \
 	crc.c \
 	encoder.c \
 	encoder_framing.c \
diff --git a/src/libFLAC/Makefile.lite b/src/libFLAC/Makefile.lite
index 7fec2dba..de9c3759 100644
--- a/src/libFLAC/Makefile.lite
+++ b/src/libFLAC/Makefile.lite
@@ -8,6 +8,7 @@ DEBUG_CFLAGS = -DFLAC_OVERFLOW_DETECT
 
 OBJS = \
 	bitbuffer.o \
+	bitmath.o \
 	crc.o \
 	encoder.o \
 	encoder_framing.o \
diff --git a/src/libFLAC/Makefile.vc b/src/libFLAC/Makefile.vc
index 0846c624..43355fd9 100644
--- a/src/libFLAC/Makefile.vc
+++ b/src/libFLAC/Makefile.vc
@@ -10,6 +10,7 @@
 
 C_FILES= \
 	bitbuffer.c \
+	bitmath.c \
 	crc.c \
 	encoder.c \
 	encoder_framing.c \