--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -53,10 +53,10 @@
 include(CheckCXXSourceCompiles)
 include(CheckCXXSourceRuns)
 
-set(CMAKE_C_FLAGS "-std=gnu99")
-set(CMAKE_CXX_FLAGS "-ansi -pedantic -Wall -Wextra -Wno-long-long")
+set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -std=gnu99")
+set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wall -Wextra -Wno-long-long")
 
-set(CMAKE_CXX_FLAGS_RELEASE "-O3 -mtune=native -march=native -DNDEBUG -fomit-frame-pointer -ffast-math") # TODO -Ofast GCC 4.6
+set(CMAKE_CXX_FLAGS_RELEASE "-DNDEBUG") # TODO -Ofast GCC 4.6
 set(CMAKE_C_FLAGS_RELEASE ${CMAKE_CXX_FLAGS_RELEASE})
 set(CMAKE_CXX_FLAGS_DEBUG "-g3 -DDEBUG")
 set(CMAKE_C_FLAGS_DEBUG ${CMAKE_CXX_FLAGS_DEBUG})
@@ -114,7 +114,7 @@
   OUTPUT_STRIP_TRAILING_WHITESPACE
   ERROR_QUIET
 )
-if(EXECUTE_RESULT)
+if(TRUE)
   message(STATUS "dpkg not found: No package generation.")
 else()
   message(STATUS "Debian architecture: ${CPACK_DEBIAN_PACKAGE_ARCHITECTURE}")