diff --git a/lib/Sema/CSBindings.cpp b/lib/Sema/CSBindings.cpp
index a05f865768a32..b159a8494c566 100644
--- a/lib/Sema/CSBindings.cpp
+++ b/lib/Sema/CSBindings.cpp
@@ -1072,7 +1072,7 @@ bool TypeVariableBinding::attempt(ConstraintSystem &cs) const {
   auto *dstLocator = TypeVar->getImpl().getLocator();
 
   if (Binding.hasDefaultedLiteralProtocol()) {
-    type = cs.openUnboundGenericType(type, dstLocator);
+    type = cs.openUnboundGenericTypes(type, dstLocator);
     type = type->reconstituteSugar(/*recursive=*/false);
   }
 
diff --git a/lib/Sema/CSGen.cpp b/lib/Sema/CSGen.cpp
index 15b1d5ee7a85a..a384e5e54f6ed 100644
--- a/lib/Sema/CSGen.cpp
+++ b/lib/Sema/CSGen.cpp
@@ -1446,7 +1446,7 @@ namespace {
         if (auto *PD = dyn_cast<ParamDecl>(VD)) {
           if (!CS.hasType(PD)) {
             if (knownType && knownType->hasUnboundGenericType())
-              knownType = CS.openUnboundGenericType(knownType, locator);
+              knownType = CS.openUnboundGenericTypes(knownType, locator);
 
             CS.setType(
                 PD, knownType ? knownType
@@ -1521,7 +1521,7 @@ namespace {
       if (!type || type->hasError()) return Type();
       
       auto locator = CS.getConstraintLocator(E);
-      type = CS.openUnboundGenericType(type, locator);
+      type = CS.openUnboundGenericTypes(type, locator);
       return MetatypeType::get(type);
     }
 
@@ -2205,7 +2205,7 @@ namespace {
           Type externalType;
           if (param->getTypeRepr()) {
             auto declaredTy = param->getType();
-            externalType = CS.openUnboundGenericType(declaredTy, paramLoc);
+            externalType = CS.openUnboundGenericTypes(declaredTy, paramLoc);
           } else {
             // Let's allow parameters which haven't been explicitly typed
             // to become holes by default, this helps in situations like
@@ -2439,7 +2439,7 @@ namespace {
         // Look through reference storage types.
         type = type->getReferenceStorageReferent();
 
-        Type openedType = CS.openUnboundGenericType(type, locator);
+        Type openedType = CS.openUnboundGenericTypes(type, locator);
         assert(openedType);
 
         auto *subPattern = cast<TypedPattern>(pattern)->getSubPattern();
@@ -2541,7 +2541,7 @@ namespace {
         if (!castType)
           return Type();
 
-        castType = CS.openUnboundGenericType(
+        castType = CS.openUnboundGenericTypes(
             castType,
             locator.withPathElement(LocatorPathElt::PatternMatch(pattern)));
 
@@ -2607,7 +2607,7 @@ namespace {
           if (!parentType)
             return Type();
 
-          parentType = CS.openUnboundGenericType(
+          parentType = CS.openUnboundGenericTypes(
               parentType, CS.getConstraintLocator(
                               locator, {LocatorPathElt::PatternMatch(pattern),
                                         ConstraintLocator::ParentType}));
@@ -3100,7 +3100,7 @@ namespace {
 
       // Open the type we're casting to.
       const auto toType =
-          CS.openUnboundGenericType(type, CS.getConstraintLocator(expr));
+          CS.openUnboundGenericTypes(type, CS.getConstraintLocator(expr));
       if (repr) CS.setType(repr, toType);
 
       auto fromType = CS.getType(fromExpr);
@@ -3127,7 +3127,7 @@ namespace {
 
       // Open the type we're casting to.
       const auto toType =
-          CS.openUnboundGenericType(type, CS.getConstraintLocator(expr));
+          CS.openUnboundGenericTypes(type, CS.getConstraintLocator(expr));
       if (repr) CS.setType(repr, toType);
 
       auto fromType = CS.getType(expr->getSubExpr());
@@ -3160,7 +3160,7 @@ namespace {
 
       // Open the type we're casting to.
       const auto toType =
-          CS.openUnboundGenericType(type, CS.getConstraintLocator(expr));
+          CS.openUnboundGenericTypes(type, CS.getConstraintLocator(expr));
       if (repr) CS.setType(repr, toType);
 
       auto fromType = CS.getType(fromExpr);
@@ -3189,7 +3189,7 @@ namespace {
       // Open up the type we're checking.
       // FIXME: Locator for the cast type?
       const auto toType =
-          CS.openUnboundGenericType(type, CS.getConstraintLocator(expr));
+          CS.openUnboundGenericTypes(type, CS.getConstraintLocator(expr));
       CS.setType(expr->getCastTypeRepr(), toType);
 
       // Add a checked cast constraint.
@@ -3469,7 +3469,7 @@ namespace {
             rootRepr, TypeResolverContext::InExpression);
         if (!rootObjectTy || rootObjectTy->hasError())
           return Type();
-        rootObjectTy = CS.openUnboundGenericType(rootObjectTy, locator);
+        rootObjectTy = CS.openUnboundGenericTypes(rootObjectTy, locator);
         // Allow \Derived.property to be inferred as \Base.property to
         // simulate a sort of covariant conversion from
         // KeyPath<Derived, T> to KeyPath<Base, T>.
diff --git a/lib/Sema/ConstraintSystem.cpp b/lib/Sema/ConstraintSystem.cpp
index 52eb827460772..7b28796ae60b1 100644
--- a/lib/Sema/ConstraintSystem.cpp
+++ b/lib/Sema/ConstraintSystem.cpp
@@ -661,7 +661,7 @@ ConstraintSystem::openUnboundGenericType(UnboundGenericType *unbound,
   auto unboundDecl = unbound->getDecl();
   auto parentTy = unbound->getParent();
   if (parentTy) {
-    parentTy = openUnboundGenericType(parentTy, locator);
+    parentTy = openUnboundGenericTypes(parentTy, locator);
     unbound = UnboundGenericType::get(unboundDecl, parentTy,
                                       getASTContext());
   }
@@ -782,7 +782,7 @@ static void checkNestedTypeConstraints(ConstraintSystem &cs, Type type,
   checkNestedTypeConstraints(cs, parentTy, locator);
 }
 
-Type ConstraintSystem::openUnboundGenericType(
+Type ConstraintSystem::openUnboundGenericTypes(
     Type type, ConstraintLocatorBuilder locator) {
   assert(!type->getCanonicalType()->hasTypeParameter());
 
@@ -1235,7 +1235,7 @@ ConstraintSystem::getTypeOfReference(ValueDecl *value,
     checkNestedTypeConstraints(*this, type, locator);
 
     // Open the type.
-    type = openUnboundGenericType(type, locator);
+    type = openUnboundGenericTypes(type, locator);
 
     // Module types are not wrapped in metatypes.
     if (type->is<ModuleType>())
@@ -1491,7 +1491,7 @@ ConstraintSystem::getTypeOfMemberReference(
     checkNestedTypeConstraints(*this, memberTy, locator);
 
     // Open the type if it was a reference to a generic type.
-    memberTy = openUnboundGenericType(memberTy, locator);
+    memberTy = openUnboundGenericTypes(memberTy, locator);
 
     // Wrap it in a metatype.
     memberTy = MetatypeType::get(memberTy);
diff --git a/lib/Sema/ConstraintSystem.h b/lib/Sema/ConstraintSystem.h
index d458367f0f40b..4c93b2ef74571 100644
--- a/lib/Sema/ConstraintSystem.h
+++ b/lib/Sema/ConstraintSystem.h
@@ -3420,7 +3420,7 @@ class ConstraintSystem {
   /// \param type The type to open.
   ///
   /// \returns The opened type.
-  Type openUnboundGenericType(Type type, ConstraintLocatorBuilder locator);
+  Type openUnboundGenericTypes(Type type, ConstraintLocatorBuilder locator);
 
   /// "Open" the given type by replacing any occurrences of generic
   /// parameter types and dependent member types with fresh type variables.
diff --git a/lib/Sema/TypeCheckPropertyWrapper.cpp b/lib/Sema/TypeCheckPropertyWrapper.cpp
index 5c1cdfc6f9987..6866e96a2100c 100644
--- a/lib/Sema/TypeCheckPropertyWrapper.cpp
+++ b/lib/Sema/TypeCheckPropertyWrapper.cpp
@@ -619,7 +619,7 @@ PropertyWrapperBackingPropertyTypeRequest::evaluate(
     
     // Open the type.
     Type openedWrapperType =
-      cs.openUnboundGenericType(rawWrapperType, emptyLocator);
+      cs.openUnboundGenericTypes(rawWrapperType, emptyLocator);
     if (!outermostOpenedWrapperType)
       outermostOpenedWrapperType = openedWrapperType;