diff --git a/CMakeLists.txt b/CMakeLists.txt
index f4d3b6d2..448f5ee8 100755
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -58,10 +58,10 @@ endif()
 
 if (CMAKE_BUILD_TYPE STREQUAL Debug)
     set(LIBRARY_COMPILE_FLAGS -shared -fPIC -g -D_GNU_SOURCE -Wall)
-    set(TEST_COMPILE_FLAGS -o1)
+    set(TEST_COMPILE_FLAGS -O1)
 else()
     set(LIBRARY_COMPILE_FLAGS -shared -fPIC -D_GNU_SOURCE -fvisibility=hidden -Wall)
-    set(TEST_COMPILE_FLAGS -o1)
+    set(TEST_COMPILE_FLAGS -O1)
 endif()
 
 include_directories(${CUDA_HOME}/include)