diff --git a/.config/dotnet-tools.json b/.config/dotnet-tools.json
index 42d989f0a1..146c46e4fb 100644
--- a/.config/dotnet-tools.json
+++ b/.config/dotnet-tools.json
@@ -21,7 +21,7 @@
       ]
     },
     "fantomas-tool": {
-      "version": "4.5.0-alpha-019",
+      "version": "4.5.0-beta-001",
       "commands": [
         "fantomas"
       ]
diff --git a/src/Fantomas/Context.fs b/src/Fantomas/Context.fs
index 25b6a4fd70..9ff57d4363 100644
--- a/src/Fantomas/Context.fs
+++ b/src/Fantomas/Context.fs
@@ -1427,7 +1427,7 @@ let internal addExtraNewlineIfLeadingWasMultiline leading sepNlnConsideringTrivi
             +> continuation)
 
 type internal ColMultilineItem =
-    ColMultilineItem of
+    | ColMultilineItem of
         // current expression
         expr: (Context -> Context) *
         // sepNln of current item