diff --git a/src/json.c b/src/json.c
index 64ef93f..6d7b193 100644
--- a/src/json.c
+++ b/src/json.c
@@ -215,7 +215,7 @@
 
 	case VAR_NUMBER:
 	    vim_snprintf((char *)numbuf, NUMBUFLEN, "%lld",
-						(long_long_T)val->vval.v_number);
+					      (long_long_T)val->vval.v_number);
 	    ga_concat(gap, numbuf);
 	    break;
 
@@ -350,6 +350,7 @@
 	    break;
 #endif
 	case VAR_UNKNOWN:
+	case VAR_VOID:
 	    internal_error("json_encode_item()");
 	    return FAIL;
     }