diff --git a/CMakeLists.txt b/CMakeLists.txt
index f8ea2189..55fc44a1 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -1,5 +1,7 @@
 cmake_minimum_required(VERSION 3.10)
 
+set (CMAKE_CONFIGURATION_TYPES "Debug;Release")
+
 project(lwIP)
 
 # Example lwIP application
diff --git a/contrib/ports/unix/check/CMakeLists.txt b/contrib/ports/unix/check/CMakeLists.txt
index 54f3d202..68833163 100644
--- a/contrib/ports/unix/check/CMakeLists.txt
+++ b/contrib/ports/unix/check/CMakeLists.txt
@@ -1,5 +1,7 @@
 cmake_minimum_required(VERSION 3.8)
 
+set (CMAKE_CONFIGURATION_TYPES "Debug;Release")
+
 project(lwipunittests C)
 
 if (NOT CMAKE_SYSTEM_NAME STREQUAL "Linux" AND NOT CMAKE_SYSTEM_NAME STREQUAL "Darwin")