diff --git a/setup.cfg b/setup.cfg
index 38e82f81d..e7f6ea922 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -100,10 +100,6 @@ install_requires =
     # A new enough version to support custom JSON encoders.
     eliot >= 1.13.0
 
-    # Pyrsistent 0.17.0 (which we use by way of Eliot) has dropped
-    # Python 2 entirely; stick to the version known to work for us.
-    pyrsistent
-
     # A great way to define types of values.
     attrs >= 18.2.0