diff --git a/src/drivers/boards/mindpx-v2/mindpx_can.c b/src/drivers/boards/mindpx-v2/mindpx_can.c
index 84c7a28bf2..2e818c5b10 100644
--- a/src/drivers/boards/mindpx-v2/mindpx_can.c
+++ b/src/drivers/boards/mindpx-v2/mindpx_can.c
@@ -96,7 +96,7 @@
 /************************************************************************************
  * Public Functions
  ************************************************************************************/
-
+int can_devinit(void);
 /************************************************************************************
  * Name: can_devinit
  *
@@ -141,4 +141,4 @@ int can_devinit(void)
 	return OK;
 }
 
-#endif
\ No newline at end of file
+#endif
diff --git a/src/drivers/boards/px4fmu-v2/px4fmu_can.c b/src/drivers/boards/px4fmu-v2/px4fmu_can.c
index 62f170957d..2aaae19a87 100644
--- a/src/drivers/boards/px4fmu-v2/px4fmu_can.c
+++ b/src/drivers/boards/px4fmu-v2/px4fmu_can.c
@@ -96,6 +96,7 @@
 /************************************************************************************
  * Public Functions
  ************************************************************************************/
+int can_devinit(void);
 
 /************************************************************************************
  * Name: can_devinit
@@ -141,4 +142,4 @@ int can_devinit(void)
 	return OK;
 }
 
-#endif
\ No newline at end of file
+#endif
diff --git a/src/drivers/boards/px4fmu-v4/px4fmu_can.c b/src/drivers/boards/px4fmu-v4/px4fmu_can.c
index 62f170957d..2aaae19a87 100644
--- a/src/drivers/boards/px4fmu-v4/px4fmu_can.c
+++ b/src/drivers/boards/px4fmu-v4/px4fmu_can.c
@@ -96,6 +96,7 @@
 /************************************************************************************
  * Public Functions
  ************************************************************************************/
+int can_devinit(void);
 
 /************************************************************************************
  * Name: can_devinit
@@ -141,4 +142,4 @@ int can_devinit(void)
 	return OK;
 }
 
-#endif
\ No newline at end of file
+#endif