Index: ram/ettval.c
===================================================================
--- ram/ettval.c	(revision d235320034dd5cb2eba11be522aa05c15bac38d2)
+++ ram/ettval.c	(revision 202bf8cdad3fa90dd3bcdab0581743733f8bf3ff)
@@ -141,8 +141,8 @@
 	} else {
 
-		ebuf[ec] = k + '0';
+		ebuf[ec] = (int8_t)(k + '0');
 		ebuf[5] = '\0';
 
-		dspbuf[0] = k + '0';
+		dspbuf[0] = (int8_t)(k + '0');
 		dspbuf[1] = '\0';
 	}