diff --git a/clang/lib/Sema/SemaDeclObjC.cpp b/clang/lib/Sema/SemaDeclObjC.cpp
--- a/clang/lib/Sema/SemaDeclObjC.cpp
+++ b/clang/lib/Sema/SemaDeclObjC.cpp
@@ -4438,6 +4438,11 @@
                                     ResultTypeCompatibilityKind RTC) {
   if (!ObjCMethod)
     return;
+  auto IsMethodInCurrentClass = [CurrentClass](const ObjCMethodDecl *M) {
+    // Checking canonical decl works across modules.
+    return M->getClassInterface()->getCanonicalDecl() ==
+           CurrentClass->getCanonicalDecl();
+  };
   // Search for overridden methods and merge information down from them.
   OverrideSearch overrides(*this, ObjCMethod);
   // Keep track if the method overrides any method in the class's base classes,
@@ -4449,8 +4454,7 @@
   for (ObjCMethodDecl *overridden : overrides) {
     if (!hasOverriddenMethodsInBaseOrProtocol) {
       if (isa<ObjCProtocolDecl>(overridden->getDeclContext()) ||
-          CurrentClass != overridden->getClassInterface() ||
-          overridden->isOverriding()) {
+          !IsMethodInCurrentClass(overridden) || overridden->isOverriding()) {
         CheckObjCMethodDirectOverrides(ObjCMethod, overridden);
         hasOverriddenMethodsInBaseOrProtocol = true;
       } else if (isa<ObjCImplDecl>(ObjCMethod->getDeclContext())) {
@@ -4475,7 +4479,7 @@
               OverrideSearch overrides(*this, overridden);
               for (ObjCMethodDecl *SuperOverridden : overrides) {
                 if (isa<ObjCProtocolDecl>(SuperOverridden->getDeclContext()) ||
-                    CurrentClass != SuperOverridden->getClassInterface()) {
+                    !IsMethodInCurrentClass(SuperOverridden)) {
                   CheckObjCMethodDirectOverrides(ObjCMethod, SuperOverridden);
                   hasOverriddenMethodsInBaseOrProtocol = true;
                   overridden->setOverriding(true);
diff --git a/clang/test/Modules/override.m b/clang/test/Modules/override.m
new file mode 100644
--- /dev/null
+++ b/clang/test/Modules/override.m
@@ -0,0 +1,69 @@
+// UNSUPPORTED: -aix
+// RUN: rm -rf %t
+// RUN: split-file %s %t
+// RUN: %clang_cc1 -fsyntax-only -I%t/include %t/test.m \
+// RUN:            -fmodules -fimplicit-module-maps -fmodules-cache-path=%t/modules.cache -fmodule-name=CheckOverride
+
+// Test that if we have the same method in a different module, it's not an
+// override as it is the same method and it has the same DeclContext but a
+// different object in the memory.
+
+
+//--- include/CheckOverride.h
+@interface NSObject
+@end
+
+@interface CheckOverrideInterfaceOnly: NSObject
+- (void)potentialOverrideInterfaceOnly;
+@end
+
+@interface CheckOverrideCategoryOnly: NSObject
+@end
+@interface CheckOverrideCategoryOnly(CategoryOnly)
+- (void)potentialOverrideCategoryOnly;
+@end
+
+@interface CheckOverrideImplementationOfInterface: NSObject
+- (void)potentialOverrideImplementationOfInterface;
+@end
+
+@interface CheckOverrideImplementationOfCategory: NSObject
+@end
+@interface CheckOverrideImplementationOfCategory(CategoryImpl)
+- (void)potentialOverrideImplementationOfCategory;
+@end
+
+//--- include/Redirect.h
+// Ensure CheckOverride is imported as the module despite all `-fmodule-name` flags.
+#import <CheckOverride.h>
+
+//--- include/module.modulemap
+module CheckOverride {
+  header "CheckOverride.h"
+}
+module Redirect {
+  header "Redirect.h"
+  export *
+}
+
+//--- test.m
+#import <CheckOverride.h>
+#import <Redirect.h>
+
+@implementation CheckOverrideImplementationOfInterface
+- (void)potentialOverrideImplementationOfInterface {}
+@end
+
+@implementation CheckOverrideImplementationOfCategory
+- (void)potentialOverrideImplementationOfCategory {}
+@end
+
+void triggerOverrideCheck(CheckOverrideInterfaceOnly *intfOnly,
+                          CheckOverrideCategoryOnly *catOnly,
+                          CheckOverrideImplementationOfInterface *intfImpl,
+                          CheckOverrideImplementationOfCategory *catImpl) {
+  [intfOnly potentialOverrideInterfaceOnly];
+  [catOnly potentialOverrideCategoryOnly];
+  [intfImpl potentialOverrideImplementationOfInterface];
+  [catImpl potentialOverrideImplementationOfCategory];
+}