diff --git a/lib/Sema/DerivedConformanceCaseIterable.cpp b/lib/Sema/DerivedConformanceCaseIterable.cpp
index 19dee6674aa28..bc809b4e53930 100644
--- a/lib/Sema/DerivedConformanceCaseIterable.cpp
+++ b/lib/Sema/DerivedConformanceCaseIterable.cpp
@@ -113,9 +113,6 @@ ValueDecl *DerivedConformance::deriveCaseIterable(ValueDecl *requirement) {
 }
 
 Type DerivedConformance::deriveCaseIterable(AssociatedTypeDecl *assocType) {
-  if (checkAndDiagnoseDisallowedContext(assocType))
-    return nullptr;
-
   // Check that we can actually derive CaseIterable for this type.
   if (!canDeriveConformance(Nominal))
     return nullptr;
diff --git a/lib/Sema/DerivedConformanceDifferentiable.cpp b/lib/Sema/DerivedConformanceDifferentiable.cpp
index 51a7ea9b77d57..8b9c3fb42b230 100644
--- a/lib/Sema/DerivedConformanceDifferentiable.cpp
+++ b/lib/Sema/DerivedConformanceDifferentiable.cpp
@@ -895,9 +895,6 @@ DerivedConformance::deriveDifferentiable(AssociatedTypeDecl *requirement) {
                            diag::broken_differentiable_requirement);
     return std::make_pair(nullptr, nullptr);
   }
-  // Diagnose conformances in disallowed contexts.
-  if (checkAndDiagnoseDisallowedContext(requirement))
-    return std::make_pair(nullptr, nullptr);
 
   // Start an error diagnostic before attempting derivation.
   // If derivation succeeds, cancel the diagnostic.
diff --git a/test/AutoDiff/Sema/DerivedConformances/Inputs/class_differentiable_other_module.swift b/test/AutoDiff/Sema/DerivedConformances/Inputs/class_differentiable_other_module.swift
index 99435939c4df1..15cfbf3a5ec63 100644
--- a/test/AutoDiff/Sema/DerivedConformances/Inputs/class_differentiable_other_module.swift
+++ b/test/AutoDiff/Sema/DerivedConformances/Inputs/class_differentiable_other_module.swift
@@ -1,9 +1,9 @@
 import _Differentiation
 
-// expected-note @+1 {{type declared here}}
+// expected-note @+1 2 {{type declared here}}
 class OtherFileNonconforming {}
 
-// expected-note @+1 {{type declared here}}
+// expected-note @+1 2 {{type declared here}}
 class GenericOtherFileNonconforming<T: Differentiable> {
   var x: T
 }
diff --git a/test/AutoDiff/Sema/DerivedConformances/Inputs/struct_differentiable_other_module.swift b/test/AutoDiff/Sema/DerivedConformances/Inputs/struct_differentiable_other_module.swift
index c3699349d3404..267eb6ef00992 100644
--- a/test/AutoDiff/Sema/DerivedConformances/Inputs/struct_differentiable_other_module.swift
+++ b/test/AutoDiff/Sema/DerivedConformances/Inputs/struct_differentiable_other_module.swift
@@ -1,9 +1,9 @@
 import _Differentiation
 
-// expected-note @+1 {{type declared here}}
+// expected-note @+1 2 {{type declared here}}
 struct OtherFileNonconforming {}
 
-// expected-note @+1 {{type declared here}}
+// expected-note @+1 2 {{type declared here}}
 struct GenericOtherFileNonconforming<T: Differentiable> {
   var x: T
 }
diff --git a/test/AutoDiff/Sema/DerivedConformances/class_differentiable.swift b/test/AutoDiff/Sema/DerivedConformances/class_differentiable.swift
index 220aba234b60f..4b1110b39636e 100644
--- a/test/AutoDiff/Sema/DerivedConformances/class_differentiable.swift
+++ b/test/AutoDiff/Sema/DerivedConformances/class_differentiable.swift
@@ -570,10 +570,8 @@ class WrappedProperties: Differentiable {
 
 // Test derived conformances in disallowed contexts.
 
-// expected-error @+2 {{type 'OtherFileNonconforming' does not conform to protocol 'Differentiable'}}
-// expected-error @+1 {{implementation of 'Differentiable' cannot be automatically synthesized in an extension in a different file to the type}}
+// expected-error @+1 2 {{implementation of 'Differentiable' cannot be automatically synthesized in an extension in a different file to the type}}
 extension OtherFileNonconforming: Differentiable {}
 
-// expected-error @+2 {{type 'GenericOtherFileNonconforming<T>' does not conform to protocol 'Differentiable'}}
-// expected-error @+1 {{implementation of 'Differentiable' cannot be automatically synthesized in an extension in a different file to the type}}
+// expected-error @+1 2 {{implementation of 'Differentiable' cannot be automatically synthesized in an extension in a different file to the type}}
 extension GenericOtherFileNonconforming: Differentiable {}
diff --git a/test/AutoDiff/Sema/DerivedConformances/struct_differentiable.swift b/test/AutoDiff/Sema/DerivedConformances/struct_differentiable.swift
index 9da7d49f7c9de..02f9154426cf4 100644
--- a/test/AutoDiff/Sema/DerivedConformances/struct_differentiable.swift
+++ b/test/AutoDiff/Sema/DerivedConformances/struct_differentiable.swift
@@ -383,10 +383,8 @@ struct WrappedProperties: Differentiable {
 
 // Verify that cross-file derived conformances are disallowed.
 
-// expected-error @+2 {{type 'OtherFileNonconforming' does not conform to protocol 'Differentiable'}}
-// expected-error @+1 {{implementation of 'Differentiable' cannot be automatically synthesized in an extension in a different file to the type}}
+// expected-error @+1 2 {{implementation of 'Differentiable' cannot be automatically synthesized in an extension in a different file to the type}}
 extension OtherFileNonconforming: Differentiable {}
 
-// expected-error @+2 {{type 'GenericOtherFileNonconforming<T>' does not conform to protocol 'Differentiable'}}
-// expected-error @+1 {{implementation of 'Differentiable' cannot be automatically synthesized in an extension in a different file to the type}}
+// expected-error @+1 2 {{implementation of 'Differentiable' cannot be automatically synthesized in an extension in a different file to the type}}
 extension GenericOtherFileNonconforming: Differentiable {}
diff --git a/test/Sema/Inputs/enum_conformance_synthesis_other.swift b/test/Sema/Inputs/enum_conformance_synthesis_other.swift
index a8c67dc221b4f..275d8a9de78cb 100644
--- a/test/Sema/Inputs/enum_conformance_synthesis_other.swift
+++ b/test/Sema/Inputs/enum_conformance_synthesis_other.swift
@@ -29,3 +29,7 @@ extension ImpliedMain: ImplierMain {}
 enum ImpliedOther: ImplierOther {
     case a(Int)
 }
+
+enum CaseIterableAcrossFiles {
+  case A
+}
diff --git a/test/Sema/enum_conformance_synthesis.swift b/test/Sema/enum_conformance_synthesis.swift
index 189d00a3851c6..494d1b3480b32 100644
--- a/test/Sema/enum_conformance_synthesis.swift
+++ b/test/Sema/enum_conformance_synthesis.swift
@@ -224,7 +224,12 @@ enum Complex2 {
 }
 extension Complex2 : Hashable {}
 extension Complex2 : CaseIterable {}  // expected-error {{type 'Complex2' does not conform to protocol 'CaseIterable'}}
-extension FromOtherFile: CaseIterable {} // expected-error {{cannot be automatically synthesized in an extension in a different file to the type}} expected-error {{does not conform to protocol 'CaseIterable'}}
+extension FromOtherFile: CaseIterable {} // expected-error {{cannot be automatically synthesized in an extension in a different file to the type}}
+extension CaseIterableAcrossFiles: CaseIterable {
+  public static var allCases: [CaseIterableAcrossFiles] {
+    return [ .A ]
+  }
+}
 
 // No explicit conformance and it cannot be derived.
 enum NotExplicitlyHashableAndCannotDerive {