diff --git a/bilby/core/prior/base.py b/bilby/core/prior/base.py
index 802d5f6f12f0ed15e44b76514809832c406f16f3..2091c1f1a89454c410691dce8ff92e0e56ff24b0 100644
--- a/bilby/core/prior/base.py
+++ b/bilby/core/prior/base.py
@@ -424,7 +424,7 @@ class Prior(object):
             val = other_cls.from_repr(vals)
         else:
             try:
-                val = eval(val, dict(), dict(np=np))
+                val = eval(val, dict(), dict(np=np, inf=np.inf, pi=np.pi))
             except NameError:
                 raise TypeError(
                     "Cannot evaluate prior, "