diff -ur v13/ezyaml.c v14/ezyaml.c
--- v13/ezyaml.c	2018-09-08 18:08:45.000000000 +0900
+++ v14/ezyaml.c	2018-09-09 05:08:20.000000000 +0900
@@ -622,7 +622,12 @@
 	}
 	if(obj->typ == OBJ_TYP_DOUBLE){
 		char buf[1024];
-		sprintf(buf, "%g", obj->any.d);
+		double d = obj->any.d;
+		if( (int)d == d ){
+			sprintf(buf, "%d.0", (int)d);
+		}else{
+			sprintf(buf, "%g", d);
+		}
 		return str_new(buf);
 	}
 	return str_new(""); /* ! */