$OpenBSD$

Index: source/CMakeLists.txt
--- source/CMakeLists.txt.orig
+++ source/CMakeLists.txt
@@ -99,8 +99,8 @@ else()
     add_definitions(-D_LARGEFILE64_SOURCE -D_LARGEFILE_SOURCE)
 
     set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -pipe -Wall -Wno-unused-function -fvisibility=hidden -Winvalid-pch")
-    set(CMAKE_C_FLAGS_DEBUG "${CMAKE_C_FLAGS_DEBUG} -O0 -D_DEBUG")
-    set(CMAKE_C_FLAGS_RELEASE "${CMAKE_C_FLAGS_RELEASE} -fno-strict-aliasing -ffast-math -funroll-loops -msse2 -O2")
+    set(CMAKE_C_FLAGS_DEBUG "${CMAKE_C_FLAGS_DEBUG} -D_DEBUG")
+    set(CMAKE_C_FLAGS_RELEASE "${CMAKE_C_FLAGS_RELEASE} -fno-strict-aliasing -ffast-math -funroll-loops -msse2")
 
     set(CMAKE_CXX_FLAGS "${CMAKE_C_FLAGS} -std=c++11")
     set(CMAKE_CXX_FLAGS_DEBUG "${CMAKE_C_FLAGS_DEBUG}")
