diff --git a/CMakeLists.txt b/CMakeLists.txt
index dad61911d..4a9360647 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -16,6 +16,14 @@ if(COMMAND cmake_policy)
 endif()
 
 message("CMAKE Build type: ${CMAKE_BUILD_TYPE}")
+# Set a default build type if none was specified
+if(NOT CMAKE_BUILD_TYPE AND NOT CMAKE_CONFIGURATION_TYPES)
+  message(STATUS "Setting build type to 'Debug' as none was specified.")
+  set(CMAKE_BUILD_TYPE Debug CACHE STRING "Choose the type of build." FORCE)
+  # Set the possible values of build type for cmake-gui
+  set_property(CACHE CMAKE_BUILD_TYPE PROPERTY STRINGS "Debug" "Release"
+    "MinSizeRel" "RelWithDebInfo")
+endif()
 
 if(APPLE)
 	set(CMAKE_INSTALL_RPATH "@loader_path/../Frameworks")