diff --git a/src/main/java/istlab/KisoJikken/JCompiler.java b/src/main/java/istlab/KisoJikken/JCompiler.java
index e0713a7..54f9431 100644
--- a/src/main/java/istlab/KisoJikken/JCompiler.java
+++ b/src/main/java/istlab/KisoJikken/JCompiler.java
@@ -38,7 +38,7 @@
         ProcessBuilder processBuilder = new ProcessBuilder("bash", "-c",
                 "javac -encoding UTF-8 " + pkgname + "/*.java");
         if (App.isWindows) {
-            processBuilder = new ProcessBuilder("javac", "-encoding", "UTF-8" , pkgname + "/*.java");
+            processBuilder = new ProcessBuilder("javac", "-source","1.6","-target","1.6","-encoding", "UTF-8" , pkgname + "/*.java");
         }
         processBuilder.redirectErrorStream(true);
         JTAConsole con = new JTAConsole("(Compile) javac " + pkgname + "/*.java");