- Changed default compiler flags to include -O2

diff --git a/tests/Makefile b/tests/Makefile
index 2ebb9f5..4c97aa5 100644
--- a/tests/Makefile
+++ b/tests/Makefile
@@ -6,7 +6,7 @@
 CFLAGS	+= -I../include -D_FILE_OFFSET_BITS=64 -Wall -W -Wdeclaration-after-statement \
 			-Wno-unused-function -Wno-unused-value
 
-OFLAGS	= -O
+OFLAGS	= -O2
 LDFLAGS	+= -L../library -lpolarssl $(SYS_LDFLAGS)
 
 ifdef DEBUG