diff --git a/include/swift/SIL/AbstractionPattern.h b/include/swift/SIL/AbstractionPattern.h
index 890b6222225f7..3c5791cb99728 100644
--- a/include/swift/SIL/AbstractionPattern.h
+++ b/include/swift/SIL/AbstractionPattern.h
@@ -323,8 +323,10 @@ class AbstractionPattern {
     TheKind = unsigned(kind);
     OrigType = origType;
     GenericSig = CanGenericSignature();
-    if (OrigType->hasTypeParameter())
+    if (OrigType->hasTypeParameter()) {
+      assert(OrigType == signature->getCanonicalTypeInContext(origType));
       GenericSig = signature;
+    }
   }
 
   void initClangType(CanGenericSignature signature,
diff --git a/lib/SIL/AbstractionPattern.cpp b/lib/SIL/AbstractionPattern.cpp
index 65a6d7f145417..9a7e5de9625d4 100644
--- a/lib/SIL/AbstractionPattern.cpp
+++ b/lib/SIL/AbstractionPattern.cpp
@@ -46,12 +46,13 @@ TypeConverter::getAbstractionPattern(AbstractStorageDecl *decl,
 
 AbstractionPattern
 TypeConverter::getAbstractionPattern(SubscriptDecl *decl, bool isNonObjC) {
+  auto type = decl->getElementInterfaceType()->getCanonicalType();
   CanGenericSignature genericSig;
-  if (auto sig = decl->getGenericSignatureOfContext())
+  if (auto sig = decl->getGenericSignatureOfContext()) {
     genericSig = sig.getCanonicalSignature();
-  return AbstractionPattern(genericSig,
-                            decl->getElementInterfaceType()
-                                ->getCanonicalType());
+    type = sig->getCanonicalTypeInContext(type);
+  }
+  return AbstractionPattern(genericSig, type);
 }
 
 static const clang::Type *getClangType(const clang::Decl *decl) {
@@ -76,13 +77,15 @@ static Bridgeability getClangDeclBridgeability(const clang::Decl *decl) {
 
 AbstractionPattern
 TypeConverter::getAbstractionPattern(VarDecl *var, bool isNonObjC) {
-  CanGenericSignature genericSig;
-  if (auto sig = var->getDeclContext()->getGenericSignatureOfContext())
-    genericSig = sig.getCanonicalSignature();
-
   CanType swiftType = var->getInterfaceType()
                          ->getCanonicalType();
 
+  CanGenericSignature genericSig;
+  if (auto sig = var->getDeclContext()->getGenericSignatureOfContext()) {
+    genericSig = sig.getCanonicalSignature();
+    swiftType = genericSig->getCanonicalTypeInContext(swiftType);
+  }
+
   if (isNonObjC)
     return AbstractionPattern(genericSig, swiftType);
 
@@ -109,12 +112,15 @@ AbstractionPattern TypeConverter::getAbstractionPattern(EnumElementDecl *decl) {
          "Optional.Some does not have a unique abstraction pattern because "
          "optionals are re-abstracted");
 
+  CanType type = decl->getArgumentInterfaceType()->getCanonicalType();
+
   CanGenericSignature genericSig;
-  if (auto sig = decl->getParentEnum()->getGenericSignatureOfContext())
+  if (auto sig = decl->getParentEnum()->getGenericSignatureOfContext()) {
     genericSig = sig.getCanonicalSignature();
-  return AbstractionPattern(genericSig,
-                            decl->getArgumentInterfaceType()
-                                ->getCanonicalType());
+    type = genericSig->getCanonicalTypeInContext(type);
+  }
+
+  return AbstractionPattern(genericSig, type);
 }
 
 AbstractionPattern::EncodedForeignErrorInfo
diff --git a/lib/SIL/SILFunctionType.cpp b/lib/SIL/SILFunctionType.cpp
index 678dc1cb43872..c8303951ca489 100644
--- a/lib/SIL/SILFunctionType.cpp
+++ b/lib/SIL/SILFunctionType.cpp
@@ -293,6 +293,8 @@ CanSILFunctionType SILFunctionType::getAutoDiffDerivativeFunctionType(
   // Given a type, returns its formal SIL parameter info.
   auto getTangentParameterInfoForOriginalResult =
       [&](CanType tanType, ResultConvention origResConv) -> SILParameterInfo {
+    if (derivativeFnGenSig)
+      tanType = derivativeFnGenSig->getCanonicalTypeInContext(tanType);
     AbstractionPattern pattern(derivativeFnGenSig, tanType);
     auto &tl =
         TC.getTypeLowering(pattern, tanType, TypeExpansionContext::minimal());
@@ -317,6 +319,8 @@ CanSILFunctionType SILFunctionType::getAutoDiffDerivativeFunctionType(
   // Given a type, returns its formal SIL result info.
   auto getTangentResultInfoForOriginalParameter =
       [&](CanType tanType, ParameterConvention origParamConv) -> SILResultInfo {
+    if (derivativeFnGenSig)
+      tanType = derivativeFnGenSig->getCanonicalTypeInContext(tanType);
     AbstractionPattern pattern(derivativeFnGenSig, tanType);
     auto &tl =
         TC.getTypeLowering(pattern, tanType, TypeExpansionContext::minimal());