diff --git a/c/src/lib/libbsp/shared/dummy_printk_support.c b/c/src/lib/libbsp/shared/dummy_printk_support.c
index e0bb64c001..8273edb83a 100644
--- a/c/src/lib/libbsp/shared/dummy_printk_support.c
+++ b/c/src/lib/libbsp/shared/dummy_printk_support.c
@@ -22,7 +22,7 @@
 #include <rtems.h>
 #include <rtems/bspIo.h>
 
-void BSP_output_char_f(char c)
+static void BSP_output_char_f(char c)
 {
   /* the character just needs to disappear */
 }