--- src/backend/Filters/Makefile.in.orig	2013-12-29 20:48:20 UTC
+++ src/backend/Filters/Makefile.in
@@ -292,7 +292,7 @@ INCLUDES = \
 
 
 # doc directory
-pkgdocdir = $(prefix)/doc/@PACKAGE@
+pkgdocdir = $(datadir)/doc/@PACKAGE@
 noinst_HEADERS = \
 		CConvolutionFilter.h \
 		CArbitraryFIRFilter.h \
@@ -309,6 +309,8 @@ libFilters_la_SOURCES = \
 			CMorphingArbitraryFIRFilter.cpp \
 			CSinglePoleFilter.cpp \
 			CBiquadResFilter.cpp 
+
+AM_CXXFLAGS = @fftw3_CFLAGS@
 
 all: all-am