diff --git a/libraries/AP_HAL_Linux/RCOutput_PCA9685.cpp b/libraries/AP_HAL_Linux/RCOutput_PCA9685.cpp
index 529f073ccd..5a3c629850 100644
--- a/libraries/AP_HAL_Linux/RCOutput_PCA9685.cpp
+++ b/libraries/AP_HAL_Linux/RCOutput_PCA9685.cpp
@@ -60,7 +60,7 @@ static const AP_HAL::HAL& hal = AP_HAL_BOARD_DRIVER;
 
 LinuxRCOutput_PCA9685::LinuxRCOutput_PCA9685(bool external_clock,
                                              uint8_t channel_offset,
-                                             uint8_t oe_pin_number) :
+                                             int16_t oe_pin_number) :
     _i2c_sem(NULL),
     _enable_pin(NULL),
     _frequency(50),
@@ -95,9 +95,11 @@ void LinuxRCOutput_PCA9685::init(void* machtnicht)
     set_freq(0, 50);
 
     /* Enable PCA9685 PWM */
-    _enable_pin = hal.gpio->channel(_oe_pin_number);
-    _enable_pin->mode(HAL_GPIO_OUTPUT);
-    _enable_pin->write(0);
+    if (_oe_pin_number != -1) {
+        _enable_pin = hal.gpio->channel(_oe_pin_number);
+        _enable_pin->mode(HAL_GPIO_OUTPUT);
+        _enable_pin->write(0);
+    }
 }
 
 void LinuxRCOutput_PCA9685::reset_all_channels()
diff --git a/libraries/AP_HAL_Linux/RCOutput_PCA9685.h b/libraries/AP_HAL_Linux/RCOutput_PCA9685.h
index 5a431b7db0..0a4bf8eb72 100644
--- a/libraries/AP_HAL_Linux/RCOutput_PCA9685.h
+++ b/libraries/AP_HAL_Linux/RCOutput_PCA9685.h
@@ -6,8 +6,9 @@
 
 class Linux::LinuxRCOutput_PCA9685 : public AP_HAL::RCOutput {
     public:
+
     LinuxRCOutput_PCA9685(bool external_clock, uint8_t channel_offset,
-                          uint8_t oe_pin_number);
+                          int16_t oe_pin_number);
     ~LinuxRCOutput_PCA9685();
     void     init(void* machtnichts);
     void     reset_all_channels();
@@ -32,7 +33,7 @@ private:
 
     bool _external_clock;
     uint8_t _channel_offset;
-    uint8_t _oe_pin_number;
+    int16_t _oe_pin_number;
 };
 
 #endif // __AP_HAL_LINUX_RCOUTPUT_PCA9685_H__