diff --git a/radio/src/strhelpers.h b/radio/src/strhelpers.h
index 671c9a0b2..34429aaa6 100644
--- a/radio/src/strhelpers.h
+++ b/radio/src/strhelpers.h
@@ -23,7 +23,7 @@
 
 #include "opentx_types.h"
 
-char * strAppend(char * dest, const char * source, int len=0);
+char * strAppend(char * dest, const char * source, int len = 0);
 char * strAppendUnsigned(char * dest, uint32_t value, uint8_t digits=0, uint8_t radix=10);
 char * strAppendSigned(char * dest, int32_t value, uint8_t digits=0, uint8_t radix=10);
 char * strSetCursor(char * dest, int position);