diff --git a/ipc/contentproc/plugin-container.cpp b/ipc/contentproc/plugin-container.cpp
index f48a1d314256..5dc362600f02 100644
--- a/ipc/contentproc/plugin-container.cpp
+++ b/ipc/contentproc/plugin-container.cpp
@@ -42,7 +42,7 @@ public:
 #if defined(XP_MACOSX) && defined(MOZ_GMP_SANDBOX)
 class MacSandboxStarter : public mozilla::gmp::SandboxStarter {
 public:
-    virtual bool Start(const char *aLibPath) override {
+    bool Start(const char *aLibPath) override {
       std::string err;
       bool rv = mozilla::StartMacSandbox(mInfo, err);
       if (!rv) {
@@ -50,7 +50,7 @@ public:
       }
       return rv;
     }
-    virtual void SetSandboxInfo(MacSandboxInfo* aSandboxInfo) override {
+    void SetSandboxInfo(MacSandboxInfo* aSandboxInfo) override {
       mInfo = *aSandboxInfo;
     }
 private:
diff --git a/ipc/glue/BackgroundChildImpl.cpp b/ipc/glue/BackgroundChildImpl.cpp
index 915096e8b4e9..1cad85f35117 100644
--- a/ipc/glue/BackgroundChildImpl.cpp
+++ b/ipc/glue/BackgroundChildImpl.cpp
@@ -52,13 +52,13 @@ class TestChild final : public mozilla::ipc::PBackgroundTestChild
   }
 
 protected:
-  ~TestChild()
+  ~TestChild() override
   {
     MOZ_COUNT_DTOR(TestChild);
   }
 
 public:
-  virtual mozilla::ipc::IPCResult
+  mozilla::ipc::IPCResult
   Recv__delete__(const nsCString& aTestArg) override;
 };
 
diff --git a/ipc/glue/BackgroundParentImpl.cpp b/ipc/glue/BackgroundParentImpl.cpp
index 62622ef6b1ac..d26f7e5c406e 100644
--- a/ipc/glue/BackgroundParentImpl.cpp
+++ b/ipc/glue/BackgroundParentImpl.cpp
@@ -84,13 +84,13 @@ class TestParent final : public mozilla::ipc::PBackgroundTestParent
   }
 
 protected:
-  ~TestParent()
+  ~TestParent() override
   {
     MOZ_COUNT_DTOR(TestParent);
   }
 
 public:
-  virtual void
+  void
   ActorDestroy(ActorDestroyReason aWhy) override;
 };
 
@@ -399,7 +399,7 @@ public:
   }
 
 private:
-  ~InitUDPSocketParentCallback() = default;
+  ~InitUDPSocketParentCallback() override = default;
 
   RefPtr<UDPSocketParent> mActor;
   nsCString mFilter;
@@ -596,7 +596,7 @@ public:
   }
 
 private:
-  ~CheckPermissionRunnable()
+  ~CheckPermissionRunnable() override
   {
      NS_ProxyRelease(mBackgroundEventTarget, mActor.forget());
   }