diff --git a/Makefile.am b/Makefile.am
index a2f973d0..63b12b92 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -57,6 +57,7 @@ endif
 
 if USE_CONVOLUTION
 shairport_sync_SOURCES += FFTConvolver/AudioFFT.cpp FFTConvolver/FFTConvolver.cpp FFTConvolver/Utilities.cpp FFTConvolver/convolver.cpp
+AM_CXXFLAGS = -std=c++11 -O2
 endif
 
 if USE_DNS_SD