diff --git a/.gitmodules b/.gitmodules
index 481588c..0c3e3cf 100644
--- a/.gitmodules
+++ b/.gitmodules
@@ -13,3 +13,6 @@
 [submodule "lib/better-enums"]
 	path = lib/better-enums
 	url = https://github.com/aantron/better-enums
+[submodule "lib/tmxlite"]
+	path = lib/tmxlite
+	url = https://github.com/fallahn/tmxlite.git
diff --git a/CMakeLists.txt b/CMakeLists.txt
index 01c7780..f9d2048 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -66,6 +66,7 @@ target_include_directories(${PROJECT_NAME}
 )
 
 add_subdirectory(lib/clooneljump/src/cloonelgraphics)
+add_subdirectory(lib/tmxlite/tmxlite)
 add_subdirectory(src/gamelib)
 add_subdirectory(src/standalone)
 
diff --git a/lib/tmxlite b/lib/tmxlite
new file mode 160000
index 0000000..3934199
--- /dev/null
+++ b/lib/tmxlite
@@ -0,0 +1 @@
+Subproject commit 3934199e22d68a3a1e7c72049b5f6e85559e99dc
diff --git a/src/gamelib/CMakeLists.txt b/src/gamelib/CMakeLists.txt
index aa5832a..2d8b3b3 100644
--- a/src/gamelib/CMakeLists.txt
+++ b/src/gamelib/CMakeLists.txt
@@ -21,6 +21,7 @@ add_library(${PROJECT_NAME}
 	grid_raytrace.cpp
 	drawable.cpp
 	drawing_queue.cpp
+	assertion.cpp
 )
 set_property(TARGET ${PROJECT_NAME} PROPERTY CXX_STANDARD 14)
 set_property(TARGET ${PROJECT_NAME} PROPERTY CXX_STANDARD_REQUIRED ON)
@@ -42,6 +43,7 @@ target_link_libraries(${PROJECT_NAME}
 	PRIVATE ${PNG_LIBRARIES}
 	PUBLIC mycurry_toplevel
 	PUBLIC cloonelgraphics
+	PRIVATE tmxlite
 )
 
 target_compile_definitions(${PROJECT_NAME}