diff --git a/src/pulses_arm.cpp b/src/pulses_arm.cpp
index bca2118d6..99976224c 100644
--- a/src/pulses_arm.cpp
+++ b/src/pulses_arm.cpp
@@ -79,7 +79,7 @@ void startPulses()
 }
 
 #if defined(PCBSKY9X)
-#define PPM_PORT_PARAM uint32_t ppmPort=0
+#define PPM_PORT_PARAM uint32_t ppmPort
 #else
 #define PPM_PORT_PARAM
 #endif
diff --git a/src/sky9x/board_sky9x.h b/src/sky9x/board_sky9x.h
index 7da131eaa..aa82f3cdc 100644
--- a/src/sky9x/board_sky9x.h
+++ b/src/sky9x/board_sky9x.h
@@ -163,6 +163,8 @@ void disable_ppm2();
 void init_ssc();
 void disable_ssc();
 #define disable_pxx() disable_ssc()
+// TODO illogical in the driver :(
+void setupPulsesPPM(uint32_t ppmPort=0);
 
 // SD driver
 #if !defined(SIMU)
diff --git a/src/sky9x/pulses_driver.cpp b/src/sky9x/pulses_driver.cpp
index cec6d6b53..0c059cc23 100644
--- a/src/sky9x/pulses_driver.cpp
+++ b/src/sky9x/pulses_driver.cpp
@@ -34,15 +34,12 @@
 
 #include "../open9x.h"
 
-// TODO illogical in the driver :(
-void setupPulsesPPM(uint32_t ppmPort=0);
-
 void init_main_ppm( uint32_t period, uint32_t out_enable )
 {
   register Pio *pioptr ;
   register Pwm *pwmptr ;
 
-  setupPulsesPPM() ;
+  setupPulsesPPM(0) ;
 
   if ( out_enable )
   {