diff --git a/test_drivers/performance/Makefile b/test_drivers/performance/Makefile
index 5229558..b385445 100644
--- a/test_drivers/performance/Makefile
+++ b/test_drivers/performance/Makefile
@@ -1,5 +1,5 @@
 CC = g++
-CFLAGS = -O2
+CFLAGS = -O3
 
 iconvtest: iconvtest.cpp ../../source/utf8.h timer.h ../../source/utf8/core.h ../../source/utf8/checked.h ../../source/utf8/unchecked.h
 	$(CC) $(CFLAGS) iconvtest.cpp -oiconvtest