diff --git a/esphome/components/zephyr/core.cpp b/esphome/components/zephyr/core.cpp
index cac9be45b5..3f44ecdb4b 100644
--- a/esphome/components/zephyr/core.cpp
+++ b/esphome/components/zephyr/core.cpp
@@ -6,8 +6,8 @@
 
 namespace esphome {
 
-static int wdt_channel_id = -EINVAL;
-const device *wdt = nullptr;
+static int wdt_channel_id = -1;  // NOLINT(cppcoreguidelines-avoid-non-const-global-variables)
+static const device *const WDT = DEVICE_DT_GET(DT_ALIAS(watchdog0));
 
 void yield() { ::k_yield(); }
 uint32_t millis() { return k_ticks_to_ms_floor32(k_uptime_ticks()); }
@@ -16,22 +16,20 @@ void delayMicroseconds(uint32_t us) { ::k_usleep(us); }
 void delay(uint32_t ms) { ::k_msleep(ms); }
 
 void arch_init() {
-  wdt = DEVICE_DT_GET(DT_ALIAS(watchdog0));
-
-  if (device_is_ready(wdt)) {
+  if (device_is_ready(WDT)) {
     static wdt_timeout_cfg wdt_config{};
     wdt_config.flags = WDT_FLAG_RESET_SOC;
     wdt_config.window.max = 2000;
-    wdt_channel_id = wdt_install_timeout(wdt, &wdt_config);
+    wdt_channel_id = wdt_install_timeout(WDT, &wdt_config);
     if (wdt_channel_id >= 0) {
-      wdt_setup(wdt, WDT_OPT_PAUSE_HALTED_BY_DBG | WDT_OPT_PAUSE_IN_SLEEP);
+      wdt_setup(WDT, WDT_OPT_PAUSE_HALTED_BY_DBG | WDT_OPT_PAUSE_IN_SLEEP);
     }
   }
 }
 
 void arch_feed_wdt() {
   if (wdt_channel_id >= 0) {
-    wdt_feed(wdt, wdt_channel_id);
+    wdt_feed(WDT, wdt_channel_id);
   }
 }
 
diff --git a/esphome/core/gpio.h b/esphome/core/gpio.h
index b3f6b00196..0492c71792 100644
--- a/esphome/core/gpio.h
+++ b/esphome/core/gpio.h
@@ -78,7 +78,7 @@ class NullPin : public GPIOPin {
   std::string dump_summary() const override { return {"Not used"}; }
 };
 
-static GPIOPin *const NULL_PIN = new NullPin();
+static const GPIOPin *const NULL_PIN = new NullPin();
 
 /// Copy of GPIOPin that is safe to use from ISRs (with no virtual functions)
 class ISRInternalGPIOPin {
diff --git a/script/helpers.py b/script/helpers.py
index 24166960a2..27be1aa35d 100644
--- a/script/helpers.py
+++ b/script/helpers.py
@@ -181,7 +181,8 @@ int main() { return 0;}
             defines = []
             define_pattern = re.compile(r"-D\s*([^\s]+)")
             for match in define_pattern.findall(command):
-                defines.append(match)
+                if match not in ("_ASMLANGUAGE"):
+                    defines.append(match)
             return defines
 
         def find_cxx_path(commands):