diff --git a/3rdparty/fonts/CMakeLists.txt b/3rdparty/fonts/CMakeLists.txt
index 04982db1b..04712bd19 100644
--- a/3rdparty/fonts/CMakeLists.txt
+++ b/3rdparty/fonts/CMakeLists.txt
@@ -7,8 +7,11 @@ set (FNT_SOURCES
 
 add_library(PLIBFont STATIC ${FNT_SOURCES})
 
-target_link_libraries(PLIBFont SimGearCore)
+target_link_libraries(PLIBFont SimGearCore )
 
-target_include_directories(PLIBFont PUBLIC ${CMAKE_CURRENT_SOURCE_DIR})
+# we use <osg/GL> in fnt.h, so we need to use it
+target_include_directories(PLIBFont PUBLIC 
+	${CMAKE_CURRENT_SOURCE_DIR} 
+	${OPENSCENEGRAPH_INCLUDE_DIRS})
 
 
diff --git a/CMakeLists.txt b/CMakeLists.txt
index 90f9d326c..f0f3c1270 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -463,8 +463,8 @@ configure_file (
 # Setup build.h header, each build
 include( GenerateBuildInfo )
 
-# global includes: these are used by every singl target, so we do set them globally
-# even though that's not stricly best practice
+# global includes: these are used by every single target, so we do set them globally
+# even though that's not strictly best practice
 include_directories(${PROJECT_BINARY_DIR}/src/Include)
 include_directories(${PROJECT_BINARY_DIR}/src) # for version.h
 include_directories(${PROJECT_SOURCE_DIR}/src)
@@ -482,15 +482,7 @@ add_subdirectory(scripts)
 ### MSVC startup project - ensure you can just hit build & run in MSVC
 set_property(DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR} PROPERTY VS_STARTUP_PROJECT fgfs)
 
-#-----------------------------------------------------------------------------
-### uninstall target
-#-----------------------------------------------------------------------------
-CONFIGURE_FILE(
-    "${CMAKE_CURRENT_SOURCE_DIR}/CMakeModules/cmake_uninstall.cmake.in"
-    "${CMAKE_CURRENT_BINARY_DIR}/cmake_uninstall.cmake"
-    IMMEDIATE @ONLY)
-ADD_CUSTOM_TARGET(uninstall
-    "${CMAKE_COMMAND}" -P "${CMAKE_CURRENT_BINARY_DIR}/cmake_uninstall.cmake")
+include(Installation)
 
 # The test suite.
 enable_testing()
diff --git a/CMakeModules/Installation.cmake b/CMakeModules/Installation.cmake
index 3b0539a13..8c09d7b9e 100644
--- a/CMakeModules/Installation.cmake
+++ b/CMakeModules/Installation.cmake
@@ -14,3 +14,14 @@ if (TARGET sentry_crashpad::handler)
         install(FILES $<TARGET_FILE:sentry_crashpad::handler> DESTINATION ${CMAKE_INSTALL_BINDIR} OPTIONAL)
     endif()
 endif()
+
+#-----------------------------------------------------------------------------
+### uninstall target
+#-----------------------------------------------------------------------------
+CONFIGURE_FILE(
+    "${PROJECT_SOURCE_DIR}/CMakeModules/cmake_uninstall.cmake.in"
+    "${PROJECT_BINARY_DIR}/cmake_uninstall.cmake"
+    IMMEDIATE @ONLY)
+ADD_CUSTOM_TARGET(uninstall
+    "${CMAKE_COMMAND}" -P "${PROJECT_BINARY_DIR}/cmake_uninstall.cmake")
+
diff --git a/test_suite/CMakeLists.txt b/test_suite/CMakeLists.txt
index 7c33e2c6e..1c47b163d 100644
--- a/test_suite/CMakeLists.txt
+++ b/test_suite/CMakeLists.txt
@@ -142,6 +142,9 @@ setup_fgfs_libraries(fgfs_test_suite)
 # Additional search paths for includes.
 setup_fgfs_includes(fgfs_test_suite)
 
+# test codce includes its headers as test_suite/foo.h, so we need this
+target_include_directories(fgfs_test_suite PUBLIC ${PROJECT_SOURCE_DIR})
+
 target_compile_definitions(fgfs_test_suite PUBLIC BUILDING_TESTSUITE)
 
 # Additional libraries just for the test suite.