diff --git a/Makefile.am b/Makefile.am
index 10b2d03b..660b0fc9 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -590,7 +590,7 @@ PDIR = bindings/python
 PDOC_START = bindings/python/sigrok/core/doc_start.i
 PDOC_END = bindings/python/sigrok/core/doc_end.i
 
-setup_vars = VERSION='$(PACKAGE_VERSION)' CC='$(CXX)' CFLAGS='$(AM_CXXFLAGS) $(CXXFLAGS)' LDADD='$(PYSIGROK_LIBS)'
+setup_vars = VERSION='$(PACKAGE_VERSION)' CC='$(CXX)' CFLAGS='$(AM_CXXFLAGS) $(CXXFLAGS)' CXXFLAGS='$(AM_CXXFLAGS) $(CXXFLAGS)' LDADD='$(PYSIGROK_LIBS)'
 setup_quiet = --quiet
 setup_py = $(PYTHON) $(srcdir)/$(PDIR)/setup.py $(setup_vars) $(setup_quiet)