diff --git a/flax/builtins.py b/flax/builtins.py
index 2e6a01a..7c42fb5 100644
--- a/flax/builtins.py
+++ b/flax/builtins.py
@@ -515,7 +515,9 @@
     "˝": attrdict(
         condition=lambda links: links and links[0].arity,
         qlink=lambda links, outermost_links, i: [
-            attrdict(arity=2, call=lambda w, x: fold(links, w, x, initial=True, right=True))
+            attrdict(
+                arity=2, call=lambda w, x: fold(links, w, x, initial=True, right=True)
+            )
         ],
     ),
     "ˢ": attrdict(
@@ -632,9 +634,7 @@
     "ᵟ˝": attrdict(
         condition=lambda links: links and links[0].arity,
         qlink=lambda links, outermost_links, i: [
-            attrdict(
-                arity=2, call=lambda w, x: fold(links, w, x, initial=True)
-            )
+            attrdict(arity=2, call=lambda w, x: fold(links, w, x, initial=True))
         ],
     ),
     "ᵟᵂ": attrdict(
@@ -671,9 +671,7 @@
     "ᵟ‶": attrdict(
         condition=lambda links: links and links[0].arity,
         qlink=lambda links, outermost_links, i: [
-            attrdict(
-                arity=2, call=lambda w, x: scan(links, w, x, initial=True)
-            )
+            attrdict(arity=2, call=lambda w, x: scan(links, w, x, initial=True))
         ],
     ),
     "ᵟⁿ": attrdict(
@@ -724,7 +722,9 @@
     "‶": attrdict(
         condition=lambda links: links and links[0].arity,
         qlink=lambda links, outermost_links, i: [
-            attrdict(arity=2, call=lambda w, x: scan(links, w, x, initial=True, right=True))
+            attrdict(
+                arity=2, call=lambda w, x: scan(links, w, x, initial=True, right=True)
+            )
         ],
     ),
     "⁰": attrdict(