diff --git a/CMakeLists.txt b/CMakeLists.txt
index e445c53f..cf940940 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -64,7 +64,7 @@ if (BUILD_EMULATOR)
 
     # Set default compile flags for GCC
     if (CMAKE_COMPILER_IS_GNUCXX)
-        add_compile_options(-g -v -Wall -Wextra -Wunused -O3)
+        add_compile_options(-g -v -Wall -Wextra -Werror -Wunused -O3)
     endif (CMAKE_COMPILER_IS_GNUCXX)
 
     # WARDuino CLI
diff --git a/src/Debug/debugger.cpp b/src/Debug/debugger.cpp
index a8e3802f..58df8e9c 100644
--- a/src/Debug/debugger.cpp
+++ b/src/Debug/debugger.cpp
@@ -954,7 +954,7 @@ void Debugger::setSnapshotPolicy(Module *m, uint8_t *interruptData) {
 
 std::optional<uint32_t> getPrimitiveBeingCalled(Module *m, uint8_t *pc_ptr) {
     if (!pc_ptr) {
-        return {};
+        return std::nullopt;
     }
 
     // TODO: Support call_indirect
@@ -966,7 +966,7 @@ std::optional<uint32_t> getPrimitiveBeingCalled(Module *m, uint8_t *pc_ptr) {
             return fidx;
         }
     }
-    return {};
+    return std::nullopt;
 }
 
 void Debugger::handleSnapshotPolicy(Module *m) {