diff --git a/src/libFLAC/Makefile.am b/src/libFLAC/Makefile.am
index 94fb93e6..0ccdd031 100644
--- a/src/libFLAC/Makefile.am
+++ b/src/libFLAC/Makefile.am
@@ -4,9 +4,9 @@
 
 lib_LTLIBRARIES = libFLAC.la
 if DEBUG
-CFLAGS += @CFLAGS@ -DFLAC__OVERFLOW_DETECT
+CFLAGS += @CFLAGS@ -DFLAC__PRECOMPUTE_PARTITION_SUMS -DFLAC__OVERFLOW_DETECT
 else
-CFLAGS = @CFLAGS@
+CFLAGS = @CFLAGS@ -DFLAC__PRECOMPUTE_PARTITION_SUMS
 endif
 
 libFLAC_la_SOURCES = \
diff --git a/src/libFLAC/Makefile.lite b/src/libFLAC/Makefile.lite
index 5784461d..0fb225a1 100644
--- a/src/libFLAC/Makefile.lite
+++ b/src/libFLAC/Makefile.lite
@@ -3,6 +3,7 @@
 #
 
 LIB_NAME  = libFLAC
+DEFINES = -DFLAC__PRECOMPUTE_PARTITION_SUMS
 INCLUDES  = -I./include -I../../include
 DEBUG_CFLAGS = -DFLAC__OVERFLOW_DETECT
 
diff --git a/src/libFLAC/Makefile.vc b/src/libFLAC/Makefile.vc
index d1299bc1..e7a04bba 100644
--- a/src/libFLAC/Makefile.vc
+++ b/src/libFLAC/Makefile.vc
@@ -2,10 +2,10 @@
 
 !IFDEF DEBUG
 .c.obj:
-	$(cc) /D FLAC__OVERFLOW_DETECT /GX $(cdebug) $(cflags) /I "..\..\include" /I ".\include" -DSTRICT -YX /Od /D "_DEBUG" $<
+	$(cc) /D FLAC__PRECOMPUTE_PARTITION_SUMS /D FLAC__OVERFLOW_DETECT /GX $(cdebug) $(cflags) /I "..\..\include" /I ".\include" -DSTRICT -YX /Od /D "_DEBUG" $<
 !else
 .c.obj:
-	$(cc) /O2 $(crelease) $(cflags) /I "..\..\include" /I ".\include" -DSTRICT -YX -DNODEBUG $<
+	$(cc) /D FLAC__PRECOMPUTE_PARTITION_SUMS /O2 $(crelease) $(cflags) /I "..\..\include" /I ".\include" -DSTRICT -YX -DNODEBUG $<
 !endif
 
 C_FILES= \