diff --git a/Makefile b/Makefile
index 3f5ab295cc..1f40f9c291 100644
--- a/Makefile
+++ b/Makefile
@@ -223,6 +223,7 @@ CFLAGS      += $(ARCH_FLAGS) \
               $(DEBUG_FLAGS) \
               -std=gnu99 \
               -Wall -Wextra -Wunsafe-loop-optimizations -Wdouble-promotion \
+              -Wstrict-prototypes \
               -Werror=switch \
               -ffunction-sections \
               -fdata-sections \
diff --git a/src/main/cms/cms_menu_vtx_smartaudio.h b/src/main/cms/cms_menu_vtx_smartaudio.h
index d8aeea3ab5..e29f05d891 100644
--- a/src/main/cms/cms_menu_vtx_smartaudio.h
+++ b/src/main/cms/cms_menu_vtx_smartaudio.h
@@ -26,4 +26,4 @@
 extern CMS_Menu cmsx_menuVtxSmartAudio;
 
 void saCmsUpdate(void);
-void saCmsResetOpmodel();
+void saCmsResetOpmodel(void);
diff --git a/src/main/drivers/rx_spi.h b/src/main/drivers/rx_spi.h
index 55613b12bc..c459c4735c 100755
--- a/src/main/drivers/rx_spi.h
+++ b/src/main/drivers/rx_spi.h
@@ -20,7 +20,7 @@
 
 #define RX_SPI_MAX_PAYLOAD_SIZE 32
 
-void rxSpiDeviceInit();
+void rxSpiDeviceInit(void);
 uint8_t rxSpiTransferByte(uint8_t data);
 uint8_t rxSpiWriteByte(uint8_t data);
 uint8_t rxSpiWriteCommand(uint8_t command, uint8_t data);
diff --git a/src/main/fc/fc_core.h b/src/main/fc/fc_core.h
index 3d7d0c9a36..c63978e3f6 100644
--- a/src/main/fc/fc_core.h
+++ b/src/main/fc/fc_core.h
@@ -39,6 +39,6 @@ void tryArm(void);
 disarmReason_t getDisarmReason(void);
 
 bool isCalibrating(void);
-float getFlightTime();
+float getFlightTime(void);
 
-void fcReboot(bool bootLoader);
\ No newline at end of file
+void fcReboot(bool bootLoader);
diff --git a/src/main/fc/stats.h b/src/main/fc/stats.h
index 95bf8c2bca..275460643c 100644
--- a/src/main/fc/stats.h
+++ b/src/main/fc/stats.h
@@ -11,7 +11,7 @@ typedef struct statsConfig_s {
     uint8_t  stats_enabled;
 } statsConfig_t;
 
-uint32_t getFlyingEnergy();
+uint32_t getFlyingEnergy(void);
 void statsOnArm(void);
 void statsOnDisarm(void);
 
diff --git a/src/main/flight/pid.h b/src/main/flight/pid.h
index 013fe88df6..9cc9788177 100644
--- a/src/main/flight/pid.h
+++ b/src/main/flight/pid.h
@@ -140,8 +140,8 @@ typedef struct pidAutotuneConfig_s {
 PG_DECLARE_PROFILE(pidProfile_t, pidProfile);
 PG_DECLARE(pidAutotuneConfig_t, pidAutotuneConfig);
 
-static inline const pidBank_t * pidBank() { return STATE(FIXED_WING) ? &pidProfile()->bank_fw : &pidProfile()->bank_mc; }
-static inline pidBank_t * pidBankMutable() { return STATE(FIXED_WING) ? &pidProfileMutable()->bank_fw : &pidProfileMutable()->bank_mc; }
+static inline const pidBank_t * pidBank(void) { return STATE(FIXED_WING) ? &pidProfile()->bank_fw : &pidProfile()->bank_mc; }
+static inline pidBank_t * pidBankMutable(void) { return STATE(FIXED_WING) ? &pidProfileMutable()->bank_fw : &pidProfileMutable()->bank_mc; }
 
 extern int16_t axisPID[];
 extern int32_t axisPID_P[], axisPID_I[], axisPID_D[], axisPID_Setpoint[];
diff --git a/src/main/io/pwmdriver_i2c.c b/src/main/io/pwmdriver_i2c.c
index 2fda679d41..727b8428f9 100644
--- a/src/main/io/pwmdriver_i2c.c
+++ b/src/main/io/pwmdriver_i2c.c
@@ -30,7 +30,7 @@ pwmDriverDriver_t pwmDrivers[PWM_DRIVER_IMPLEMENTATION_COUNT] = {
     }
 };
 
-bool isPwmDriverEnabled() {
+bool isPwmDriverEnabled(void) {
     return driverEnabled;
 }
 
diff --git a/src/main/navigation/navigation.h b/src/main/navigation/navigation.h
index dffa7ad56b..d1353f2a47 100755
--- a/src/main/navigation/navigation.h
+++ b/src/main/navigation/navigation.h
@@ -382,7 +382,7 @@ void resetWaypointList(void);
 bool loadNonVolatileWaypointList(void);
 bool saveNonVolatileWaypointList(void);
 
-float RTHAltitude();
+float RTHAltitude(void);
 
 /* Geodetic functions */
 typedef enum {
@@ -438,7 +438,7 @@ bool isNavLaunchEnabled(void);
 bool isFixedWingLaunchDetected(void);
 bool isFixedWingLaunchFinishedOrAborted(void);
 
-float calculateAverageSpeed();
+float calculateAverageSpeed(void);
 
 const navigationPIDControllers_t* getNavigationPIDControllers(void);
 
diff --git a/src/main/sensors/battery.c b/src/main/sensors/battery.c
index d9ef1cb447..2fa663fd46 100644
--- a/src/main/sensors/battery.c
+++ b/src/main/sensors/battery.c
@@ -157,7 +157,7 @@ static int profile_compare(profile_comp_t *a, profile_comp_t *b) {
 }
 
 // Find profile matching plugged battery for profile_autoselect
-static int8_t profileDetect() {
+static int8_t profileDetect(void) {
     profile_comp_t profile_comp_array[MAX_BATTERY_PROFILE_COUNT];
 
     // Prepare profile sort
diff --git a/src/main/sensors/battery.h b/src/main/sensors/battery.h
index 2ce0370074..45b9affad3 100644
--- a/src/main/sensors/battery.h
+++ b/src/main/sensors/battery.h
@@ -148,6 +148,6 @@ void powerMeterUpdate(timeUs_t timeDelta);
 
 uint8_t calculateBatteryPercentage(void);
 float calculateThrottleCompensationFactor(void);
-int32_t calculateAveragePower();
-int32_t calculateAverageEfficiency();
+int32_t calculateAveragePower(void);
+int32_t calculateAverageEfficiency(void);
 int32_t heatLossesCompensatedPower(int32_t power);
diff --git a/src/main/sensors/gyro.h b/src/main/sensors/gyro.h
index 84ea3e16ca..b6802b011c 100644
--- a/src/main/sensors/gyro.h
+++ b/src/main/sensors/gyro.h
@@ -67,7 +67,7 @@ PG_DECLARE(gyroConfig_t, gyroConfig);
 bool gyroInit(void);
 void gyroInitFilters(void);
 void gyroGetMeasuredRotationRate(fpVector3_t *imuMeasuredRotationBF);
-void gyroUpdate();
+void gyroUpdate(void);
 void gyroStartCalibration(void);
 bool gyroIsCalibrationComplete(void);
 bool gyroReadTemperature(void);
diff --git a/src/utils/compiler.rb b/src/utils/compiler.rb
index 54979c193a..3a8f4d9919 100644
--- a/src/utils/compiler.rb
+++ b/src/utils/compiler.rb
@@ -61,6 +61,10 @@ class Compiler
             if flag == "" || flag == "-MMD" || flag == "-MP" || flag.start_with?("-save-temps")
                 next
             end
+            # -Wstrict-prototypes is not valid for C++
+            if flag == "-Wstrict-prototypes"
+                next
+            end
             if flag.start_with? "-std="
                 flag = "-std=c++11"
             end