1 files changed, 3 insertions, 1 deletions
diff --git a/setup.py b/setup.py
index 9e411cb35e..9e71a223c0 100644
--- a/setup.py
+++ b/setup.py
@@ -1767,7 +1767,9 @@ class PyBuildExt(build_ext):
                 ('XML_POOR_ENTROPY', '1'),
             ]
             extra_compile_args = []
-            expat_lib = []
+            # bpo-44394: libexpact uses isnan() of math.h and needs linkage
+            # against the libm
+            expat_lib = ['m']
             expat_sources = ['expat/xmlparse.c',
                              'expat/xmlrole.c',
                              'expat/xmltok.c']