diff --git a/gen/toobj.cpp b/gen/toobj.cpp
index a479a5c3..886573f5 100644
--- a/gen/toobj.cpp
+++ b/gen/toobj.cpp
@@ -146,7 +146,7 @@ llvm::Module* Module::genLLVMModule(Ir* sir)
     sir->emitFunctionBodies();
 
     // generate ModuleInfo
-    //genmoduleinfo();
+    genmoduleinfo();
 
     // emit usedArray
     if (!ir.usedArray.empty())
diff --git a/ir/irclass.cpp b/ir/irclass.cpp
index 7ec4690b..15661639 100644
--- a/ir/irclass.cpp
+++ b/ir/irclass.cpp
@@ -66,8 +66,9 @@ LLGlobalVariable * IrStruct::getClassInfoSymbol()
     IrTypeClass* tc = cinfo->type->irtype->isClass();
     assert(tc && "invalid ClassInfo type");
 
+    // classinfos cannot be constants since they're used a locks for synchronized
     classInfo = new llvm::GlobalVariable(
-        tc->getPA().get(), true, _linkage, NULL, initname, gIR->module);
+        tc->getPA().get(), false, _linkage, NULL, initname, gIR->module);
 
     return classInfo;
 }