diff --git a/src/jse/org/luaj/vm2/luajc/JavaBytecodeCompiler.java b/src/jse/org/luaj/vm2/luajc/JavaBytecodeCompiler.java
index d9310593..f0a60893 100644
--- a/src/jse/org/luaj/vm2/luajc/JavaBytecodeCompiler.java
+++ b/src/jse/org/luaj/vm2/luajc/JavaBytecodeCompiler.java
@@ -106,6 +106,7 @@ public class JavaBytecodeCompiler implements LuaCompiler {
 		String classname = filename.endsWith(".lua")? filename.substring(0,filename.length()-4): filename;
 		classname = classname.replace('/', '.');
 		classname = classname.replace('\\', '.');
+		classname = classname.replaceAll("[^\\w\\.]", "_");
 		return classname;
 	}