diff --git a/src/compiler_llvm/compilation_unit.cc b/src/compiler_llvm/compilation_unit.cc
index 266377e..5f239ab 100644
--- a/src/compiler_llvm/compilation_unit.cc
+++ b/src/compiler_llvm/compilation_unit.cc
@@ -295,7 +295,7 @@
   llvm::OwningPtr<llvm::TargetMachine> target_machine(
     target->createTargetMachine(target_triple, "", target_attr, target_options,
                                 llvm::Reloc::Static, llvm::CodeModel::Small,
-                                llvm::CodeGenOpt::Less));
+                                llvm::CodeGenOpt::Aggressive));
 
   CHECK(target_machine.get() != NULL) << "Failed to create target machine";