diff --git a/CMakeLists.txt b/CMakeLists.txt
index 46200341..9946708f 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -145,9 +145,9 @@ IF (MSGPACK_BUILD_TESTS)
 	ADD_SUBDIRECTORY (test)
 ENDIF ()
 
-IF (CMAKE_COMPILER_IS_GNUCC)
-	SET_PROPERTY (TARGET msgpack APPEND_STRING PROPERTY COMPILE_FLAGS "-Wall -DPIC")
-	SET_PROPERTY (TARGET msgpack-static APPEND_STRING PROPERTY COMPILE_FLAGS -Wall )
+IF ("${CMAKE_CXX_COMPILER_ID}" STREQUAL "Clang" OR "${CMAKE_CXX_COMPILER_ID}" STREQUAL "GNU")
+	SET_PROPERTY (TARGET msgpack APPEND_STRING PROPERTY COMPILE_FLAGS "-Wall -g -O3 -DPIC")
+	SET_PROPERTY (TARGET msgpack-static APPEND_STRING PROPERTY COMPILE_FLAGS "-Wall -g -O3" )
 ENDIF ()
 IF ("${CMAKE_CXX_COMPILER_ID}" STREQUAL "MSVC")
 	IF (CMAKE_CXX_FLAGS MATCHES "/W[0-4]")
diff --git a/test/CMakeLists.txt b/test/CMakeLists.txt
index 71ad7669..252fd164 100644
--- a/test/CMakeLists.txt
+++ b/test/CMakeLists.txt
@@ -42,8 +42,8 @@ FOREACH (source_file ${check_PROGRAMS})
 		${CMAKE_THREAD_LIBS_INIT}
 	)
 	ADD_TEST (${source_file_we} ${source_file_we})
-	IF (CMAKE_COMPILER_IS_GNUCC)
-		SET_PROPERTY (TARGET ${source_file_we} APPEND_STRING PROPERTY COMPILE_FLAGS -Wall )
+	IF ("${CMAKE_CXX_COMPILER_ID}" STREQUAL "Clang" OR "${CMAKE_CXX_COMPILER_ID}" STREQUAL "GNU")
+		SET_PROPERTY (TARGET ${source_file_we} APPEND_STRING PROPERTY COMPILE_FLAGS "-Wall -g -O3")
 	ENDIF ()
 	IF ("${CMAKE_CXX_COMPILER_ID}" STREQUAL "MSVC")
 		IF (CMAKE_CXX_FLAGS MATCHES "/W[0-4]")