diff --git a/help/help_mp-en.h b/help/help_mp-en.h
index 98d7e7adb7..d51f38ded0 100644
--- a/help/help_mp-en.h
+++ b/help/help_mp-en.h
@@ -1158,9 +1158,9 @@ static char help_text[]=
 #define MSGTR_AF_LADSPA_ErrControlBelow "%s: Input control #%d is below lower boundary of %0.4f.\n"
 #define MSGTR_AF_LADSPA_ErrControlAbove "%s: Input control #%d is above upper boundary of %0.4f.\n"
 
-// af_format.c
+// format.c
 
-#define MSGTR_AF_FORMAT_UnknownSpecial "Unknown special\n"
+#define MSGTR_AF_FORMAT_UnknownFormat "unknown-format "
 
 // ========================== INPUT =========================================
 
diff --git a/libaf/format.c b/libaf/format.c
index 1ad5f9e7de..53078d39b7 100644
--- a/libaf/format.c
+++ b/libaf/format.c
@@ -114,7 +114,7 @@ char* af_fmt2str(int format, char* str, int size)
     case(AF_FORMAT_IMA_ADPCM): 
       i+=snprintf(&str[i],size-i,"IMA-ADPCM "); break;
     default:
-      af_msg(AF_MSG_ERROR,MSGTR_AF_FORMAT_UnknownSpecial); 
+      i+=snprintf(&str[i],size-i,MSGTR_AF_FORMAT_UnknownFormat); 
     }
   }
   else{