diff --git a/CMakeLists.txt b/CMakeLists.txt
index 5bd78ef5d..85e5d3f35 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -68,6 +68,8 @@ endif (${CMAKE_SYSTEM_NAME} MATCHES "Linux")
 
 set (CMAKE_CXX_FLAGS "${_CXX11_FLAGS} ${CMAKE_CXX_FLAGS}")
 
+set (CMAKE_CXX_FLAGS "-Wall -Wsign-compare -Wreturn-type ${CMAKE_CXX_FLAGS}")
+
 if (NETBSD)
    # Since readline, etc likely to be in /usr/pkg/lib, not standard library
    # Otherwise will remove links during install