diff --git a/libpyneurosim/Makefile.am b/libpyneurosim/Makefile.am
index a115c16..6a50f9f 100644
--- a/libpyneurosim/Makefile.am
+++ b/libpyneurosim/Makefile.am
@@ -13,7 +13,7 @@ libpy3neurosim_la_SOURCES = \
 libpy3neurosim_la_HEADERS = \
   pyneurosim.h
 
-libpy3neurosim_la_CXXFLAGS = -I@PYTHON_INCLUDE@ -I$(srcdir)/../neurosim/conngen
+libpy3neurosim_la_CXXFLAGS = $(AM_CXXFLAGS) -I@PYTHON_INCLUDE@ -I$(srcdir)/../neurosim/conngen
 libpy3neurosim_la_LDFLAGS = $(top_builddir)/neurosim/libneurosim.la
 libpy3neurosim_ladir = $(includedir)/neurosim
 else
@@ -25,7 +25,7 @@ libpy2neurosim_la_SOURCES = \
 libpy2neurosim_la_HEADERS = \
   pyneurosim.h
 
-libpy2neurosim_la_CXXFLAGS = -I@PYTHON_INCLUDE@ -I$(srcdir)/../neurosim/conngen
+libpy2neurosim_la_CXXFLAGS = $(AM_CXXFLAGS) -I@PYTHON_INCLUDE@ -I$(srcdir)/../neurosim/conngen
 libpy2neurosim_la_LDFLAGS = $(top_builddir)/neurosim/libneurosim.la
 libpy2neurosim_ladir = $(includedir)/neurosim
 # generate versionless version for backwards compatibility
@@ -36,7 +36,7 @@ libpyneurosim_la_SOURCES = \
 libpyneurosim_la_HEADERS = \
   pyneurosim.h
 
-libpyneurosim_la_CXXFLAGS = -I@PYTHON_INCLUDE@ -I$(top_srcdir)
+libpyneurosim_la_CXXFLAGS = $(AM_CXXFLAGS) -I@PYTHON_INCLUDE@ -I$(top_srcdir)
 
 libpyneurosim_la_LDFLAGS = $(top_builddir)/neurosim/libneurosim.la