diff --git a/Sources/ComposableArchitecture/Effect.swift b/Sources/ComposableArchitecture/Effect.swift
index bfd4c734f23b..b71f9e56b410 100644
--- a/Sources/ComposableArchitecture/Effect.swift
+++ b/Sources/ComposableArchitecture/Effect.swift
@@ -423,7 +423,7 @@ extension Effect {
       name: String?,
       priority: TaskPriority? = nil,
       operation: @escaping @Sendable () async throws -> Success
-    ) where Failure == Error {
+    ) where Failure == any Error {
       self.init(priority: priority, operation: operation)
     }
   }
diff --git a/Sources/ComposableArchitecture/Macros.swift b/Sources/ComposableArchitecture/Macros.swift
index 036387628e4c..dfa01b5f4f19 100644
--- a/Sources/ComposableArchitecture/Macros.swift
+++ b/Sources/ComposableArchitecture/Macros.swift
@@ -56,6 +56,7 @@ public macro Reducer(state: _SynthesizedConformance..., action: _SynthesizedConf
 #endif
 public struct _SynthesizedConformance: Sendable {}
 
+@available(*, deprecated, message: "Define your conformance using an extension, instead")
 extension _SynthesizedConformance {
   /// Extends the `State` or `Action` types that ``Reducer()`` creates with the `Codable`
   /// protocol.