diff --git a/firmware/cfg/halconf.h b/firmware/cfg/halconf.h
index f0f8e3b..d021335 100644
--- a/firmware/cfg/halconf.h
+++ b/firmware/cfg/halconf.h
@@ -68,6 +68,20 @@
 #define HAL_USE_ICU                         FALSE
 #endif
 
+/**
+ * @brief   Enables the MAC subsystem.
+ */
+#if !defined(HAL_USE_MAC) || defined(__DOXYGEN__)
+#define HAL_USE_MAC                         FALSE
+#endif
+
+/**
+ * @brief   Enables the MMC_SPI subsystem.
+ */
+#if !defined(HAL_USE_MMC_SPI) || defined(__DOXYGEN__)
+#define HAL_USE_MMC_SPI                     FALSE
+#endif
+
 /**
  * @brief   Enables the PWM subsystem.
  */
@@ -89,6 +103,13 @@
 #define HAL_USE_SERIAL                      FALSE
 #endif
 
+/**
+ * @brief   Enables the SERIAL over USB subsystem.
+ */
+#if !defined(HAL_USE_SERIAL_USB) || defined(__DOXYGEN__)
+#define HAL_USE_SERIAL_USB                  FALSE
+#endif
+
 /**
  * @brief   Enables the SPI subsystem.
  */
diff --git a/firmware/heater_control.cpp b/firmware/heater_control.cpp
index 28e6ef3..cf983c5 100644
--- a/firmware/heater_control.cpp
+++ b/firmware/heater_control.cpp
@@ -68,6 +68,7 @@ static float GetDutyForState(HeaterState state, float heaterEsr)
         case HeaterState::ClosedLoop:
             // Negated because lower resistance -> hotter
             return heaterPid.GetOutput(-HEATER_TARGET_ESR, -heaterEsr);
+        default: return 0;
     }
 }
 
@@ -76,7 +77,6 @@ static HeaterState state = HeaterState::Preheat;
 static THD_WORKING_AREA(waHeaterThread, 256);
 static void HeaterThread(void*)
 {
-
     while (true)
     {
         // Read sensor state
diff --git a/firmware/lambda_conversion.cpp b/firmware/lambda_conversion.cpp
index 24f0b0f..e433008 100644
--- a/firmware/lambda_conversion.cpp
+++ b/firmware/lambda_conversion.cpp
@@ -1,5 +1,4 @@
-#pragma once
-
+#include "lambda_conversion.h"
 #include "sampling.h"
 
 static float GetPhi(float pumpCurrent)
diff --git a/firmware/pwm.cpp b/firmware/pwm.cpp
index f9a613e..13e2a65 100644
--- a/firmware/pwm.cpp
+++ b/firmware/pwm.cpp
@@ -23,6 +23,7 @@ void Pwm::Start()
             {PWM_OUTPUT_ACTIVE_HIGH | PWM_COMPLEMENTARY_OUTPUT_ACTIVE_LOW, nullptr}
         },
         0,
+        0,
         0
     };