diff -up setup.py.orig setup.py
--- setup.py.orig	2019-04-08 09:38:40.734211624 -0600
+++ setup.py	2019-04-08 09:39:15.984581008 -0600
@@ -52,9 +52,11 @@ kwds = dict(include_dirs=[opj("src"),
             undef_macros=undef_macros,
             extra_compile_args=["-Wp,-U_FORTIFY_SOURCE", "-pthread"],
             extra_link_args=["-pthread"],)
+parikwds = kwds.copy()
+parikwds['libraries'] = ['pari']
 
 extensions = [
-    Extension("cysignals.signals", ["src/cysignals/signals.pyx"], **kwds),
+    Extension("cysignals.signals", ["src/cysignals/signals.pyx"], **parikwds),
     Extension("cysignals.pysignals", ["src/cysignals/pysignals.pyx"], **kwds),
     Extension("cysignals.alarm", ["src/cysignals/alarm.pyx"], **kwds),
     Extension("cysignals.pselect", ["src/cysignals/pselect.pyx"], **kwds),