diff --git a/CMakeLists.txt b/CMakeLists.txt
index f45a805098b..aa6797b600e 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -419,6 +419,7 @@ else() # MSVC
   add_compile_flag("-Wswitch") # we explicitly expect this in the code
   add_compile_flag("-Wimplicit-fallthrough")
   add_compile_flag("-Wnon-virtual-dtor")
+  add_compile_flag("-Wsuggest-override")
 
   if(CMAKE_CXX_COMPILER_ID STREQUAL "Clang")
     # Google style requires this, so make sure we compile cleanly with it.
diff --git a/src/passes/Outlining.cpp b/src/passes/Outlining.cpp
index c52213fdc61..840a84bad37 100644
--- a/src/passes/Outlining.cpp
+++ b/src/passes/Outlining.cpp
@@ -662,7 +662,7 @@ struct ReconstructStringifyWalker
 };
 
 struct Outlining : public Pass {
-  void run(Module* module) {
+  void run(Module* module) override {
     HashStringifyWalker stringify;
     // Walk the module and create a "string representation" of the program.
     stringify.walkModule(module);
diff --git a/src/passes/Poppify.cpp b/src/passes/Poppify.cpp
index a7f3e5cccd7..c12c7203c0d 100644
--- a/src/passes/Poppify.cpp
+++ b/src/passes/Poppify.cpp
@@ -456,7 +456,7 @@ class PoppifyFunctionsPass : public Pass {
 } // anonymous namespace
 
 class PoppifyPass : public Pass {
-  void run(Module* module) {
+  void run(Module* module) override {
     PassRunner subRunner(getPassRunner());
     subRunner.add(std::make_unique<PoppifyFunctionsPass>());
     // TODO: Enable this once it handles Poppy blocks correctly