diff --git a/apps/opencs/view/render/scenewidget.cpp b/apps/opencs/view/render/scenewidget.cpp
index 5e8db03cf8..bd1f2c2d30 100644
--- a/apps/opencs/view/render/scenewidget.cpp
+++ b/apps/opencs/view/render/scenewidget.cpp
@@ -14,8 +14,8 @@
 #include <apps/opencs/view/render/lightingday.hpp>
 #include <apps/opencs/view/render/lightingnight.hpp>
 
-#include <extern/osgQt/CompositeOsgRenderer.hpp>
-#include <extern/osgQt/osgQOpenGLWidget.hpp>
+#include <osgQt/CompositeOsgRenderer.hpp>
+#include <osgQt/osgQOpenGLWidget.hpp>
 
 #include <osg/Array>
 #include <osg/Camera>
diff --git a/apps/openmw/CMakeLists.txt b/apps/openmw/CMakeLists.txt
index 9a5669c870..8570d9df60 100644
--- a/apps/openmw/CMakeLists.txt
+++ b/apps/openmw/CMakeLists.txt
@@ -170,8 +170,8 @@ target_link_libraries(openmw-lib
     ${MyGUI_LIBRARIES}
     SDL2::SDL2
     ${RecastNavigation_LIBRARIES}
-    "osg-ffmpeg-videoplayer"
-    "oics"
+    osg-ffmpeg-videoplayer
+    oics
     components
 )
 
diff --git a/apps/openmw/mwgui/videowidget.cpp b/apps/openmw/mwgui/videowidget.cpp
index 0fc555ab27..0e3ba06049 100644
--- a/apps/openmw/mwgui/videowidget.cpp
+++ b/apps/openmw/mwgui/videowidget.cpp
@@ -1,6 +1,6 @@
 #include "videowidget.hpp"
 
-#include <extern/osg-ffmpeg-videoplayer/videoplayer.hpp>
+#include <osg-ffmpeg-videoplayer/videoplayer.hpp>
 
 #include <MyGUI_RenderManager.h>
 
diff --git a/apps/openmw/mwinput/bindingsmanager.cpp b/apps/openmw/mwinput/bindingsmanager.cpp
index 9523d7ccc2..ac5d9b5730 100644
--- a/apps/openmw/mwinput/bindingsmanager.cpp
+++ b/apps/openmw/mwinput/bindingsmanager.cpp
@@ -4,8 +4,8 @@
 
 #include <MyGUI_EditBox.h>
 
-#include <extern/oics/ICSChannelListener.h>
-#include <extern/oics/ICSInputControlSystem.h>
+#include <oics/ICSChannelListener.h>
+#include <oics/ICSInputControlSystem.h>
 
 #include <components/debug/debuglog.hpp>
 #include <components/files/conversion.hpp>
diff --git a/apps/openmw/mwsound/ffmpegdecoder.cpp b/apps/openmw/mwsound/ffmpegdecoder.cpp
index df0f42bd7d..d780db8f07 100644
--- a/apps/openmw/mwsound/ffmpegdecoder.cpp
+++ b/apps/openmw/mwsound/ffmpegdecoder.cpp
@@ -8,8 +8,8 @@
 #include <components/debug/debuglog.hpp>
 #include <components/vfs/manager.hpp>
 
-#include <extern/osg-ffmpeg-videoplayer/libavformatdefines.hpp>
-#include <extern/osg-ffmpeg-videoplayer/libavutildefines.hpp>
+#include <osg-ffmpeg-videoplayer/libavformatdefines.hpp>
+#include <osg-ffmpeg-videoplayer/libavutildefines.hpp>
 
 #if OPENMW_FFMPEG_5_OR_GREATER
 #include <libavutil/channel_layout.h>
diff --git a/apps/openmw/mwsound/ffmpegdecoder.hpp b/apps/openmw/mwsound/ffmpegdecoder.hpp
index 519d160cd2..17f1301c3e 100644
--- a/apps/openmw/mwsound/ffmpegdecoder.hpp
+++ b/apps/openmw/mwsound/ffmpegdecoder.hpp
@@ -3,8 +3,8 @@
 
 #include <cstdint>
 
-#include <extern/osg-ffmpeg-videoplayer/libavformatdefines.hpp>
-#include <extern/osg-ffmpeg-videoplayer/libavutildefines.hpp>
+#include <osg-ffmpeg-videoplayer/libavformatdefines.hpp>
+#include <osg-ffmpeg-videoplayer/libavutildefines.hpp>
 
 #if defined(_MSC_VER)
 #pragma warning(push)
diff --git a/apps/openmw/mwsound/movieaudiofactory.cpp b/apps/openmw/mwsound/movieaudiofactory.cpp
index 6e479f5af2..647619d9ed 100644
--- a/apps/openmw/mwsound/movieaudiofactory.cpp
+++ b/apps/openmw/mwsound/movieaudiofactory.cpp
@@ -1,8 +1,8 @@
 #include "movieaudiofactory.hpp"
 
-#include <extern/osg-ffmpeg-videoplayer/audiodecoder.hpp>
-#include <extern/osg-ffmpeg-videoplayer/libavutildefines.hpp>
-#include <extern/osg-ffmpeg-videoplayer/videostate.hpp>
+#include <osg-ffmpeg-videoplayer/audiodecoder.hpp>
+#include <osg-ffmpeg-videoplayer/libavutildefines.hpp>
+#include <osg-ffmpeg-videoplayer/videostate.hpp>
 
 #include "../mwbase/environment.hpp"
 #include "../mwbase/soundmanager.hpp"
diff --git a/apps/openmw/mwsound/movieaudiofactory.hpp b/apps/openmw/mwsound/movieaudiofactory.hpp
index 0af1066af5..71dca9e889 100644
--- a/apps/openmw/mwsound/movieaudiofactory.hpp
+++ b/apps/openmw/mwsound/movieaudiofactory.hpp
@@ -1,7 +1,7 @@
 #ifndef OPENMW_MWSOUND_MOVIEAUDIOFACTORY_H
 #define OPENMW_MWSOUND_MOVIEAUDIOFACTORY_H
 
-#include <extern/osg-ffmpeg-videoplayer/audiofactory.hpp>
+#include <osg-ffmpeg-videoplayer/audiofactory.hpp>
 
 namespace MWSound
 {
diff --git a/components/files/hash.cpp b/components/files/hash.cpp
index 1f1839ed0c..2f5751ac97 100644
--- a/components/files/hash.cpp
+++ b/components/files/hash.cpp
@@ -1,6 +1,6 @@
 #include "hash.hpp"
 
-#include <extern/smhasher/MurmurHash3.h>
+#include <smhasher/MurmurHash3.h>
 
 #include <array>
 #include <cstdint>
diff --git a/extern/oics/CMakeLists.txt b/extern/oics/CMakeLists.txt
index 2d34f3f3e6..0f19dd8541 100644
--- a/extern/oics/CMakeLists.txt
+++ b/extern/oics/CMakeLists.txt
@@ -5,18 +5,27 @@ add_library(oics STATIC
     ICSInputControlSystem_keyboard.cpp
     ICSInputControlSystem_mouse.cpp
     ICSInputControlSystem_joystick.cpp
-    ICSPrerequisites.h
+    include/oics/ICSChannel.h
+    include/oics/ICSChannelListener.h
+    include/oics/ICSControl.h
+    include/oics/ICSControlListener.h
+    include/oics/ICSInputControlSystem.h
+    include/oics/ICSPrerequisites.h
 )
 
+target_include_directories(oics PUBLIC include)
+target_include_directories(oics PRIVATE include/oics)
+
 if(USE_SYSTEM_TINYXML)
     target_link_libraries(oics ${TinyXML_LIBRARIES})
 else()
     add_library(local_tinyxml STATIC
-        tinyxml.cpp
-        tinyxmlparser.cpp
-        tinyxmlerror.cpp
-        tinystr.cpp
+        tinyxml/tinyxml.cpp
+        tinyxml/tinyxmlparser.cpp
+        tinyxml/tinyxmlerror.cpp
+        tinyxml/tinystr.cpp
     )
+    target_include_directories(local_tinyxml PUBLIC tinyxml)
     target_link_libraries(oics local_tinyxml)
 endif()
 
diff --git a/extern/oics/ICSChannel.h b/extern/oics/include/oics/ICSChannel.h
similarity index 100%
rename from extern/oics/ICSChannel.h
rename to extern/oics/include/oics/ICSChannel.h
diff --git a/extern/oics/ICSChannelListener.h b/extern/oics/include/oics/ICSChannelListener.h
similarity index 100%
rename from extern/oics/ICSChannelListener.h
rename to extern/oics/include/oics/ICSChannelListener.h
diff --git a/extern/oics/ICSControl.h b/extern/oics/include/oics/ICSControl.h
similarity index 100%
rename from extern/oics/ICSControl.h
rename to extern/oics/include/oics/ICSControl.h
diff --git a/extern/oics/ICSControlListener.h b/extern/oics/include/oics/ICSControlListener.h
similarity index 100%
rename from extern/oics/ICSControlListener.h
rename to extern/oics/include/oics/ICSControlListener.h
diff --git a/extern/oics/ICSInputControlSystem.h b/extern/oics/include/oics/ICSInputControlSystem.h
similarity index 100%
rename from extern/oics/ICSInputControlSystem.h
rename to extern/oics/include/oics/ICSInputControlSystem.h
diff --git a/extern/oics/ICSPrerequisites.h b/extern/oics/include/oics/ICSPrerequisites.h
similarity index 100%
rename from extern/oics/ICSPrerequisites.h
rename to extern/oics/include/oics/ICSPrerequisites.h
diff --git a/extern/oics/tinystr.cpp b/extern/oics/tinyxml/tinystr.cpp
similarity index 100%
rename from extern/oics/tinystr.cpp
rename to extern/oics/tinyxml/tinystr.cpp
diff --git a/extern/oics/tinystr.h b/extern/oics/tinyxml/tinystr.h
similarity index 100%
rename from extern/oics/tinystr.h
rename to extern/oics/tinyxml/tinystr.h
diff --git a/extern/oics/tinyxml.cpp b/extern/oics/tinyxml/tinyxml.cpp
similarity index 100%
rename from extern/oics/tinyxml.cpp
rename to extern/oics/tinyxml/tinyxml.cpp
diff --git a/extern/oics/tinyxml.h b/extern/oics/tinyxml/tinyxml.h
similarity index 100%
rename from extern/oics/tinyxml.h
rename to extern/oics/tinyxml/tinyxml.h
diff --git a/extern/oics/tinyxmlerror.cpp b/extern/oics/tinyxml/tinyxmlerror.cpp
similarity index 100%
rename from extern/oics/tinyxmlerror.cpp
rename to extern/oics/tinyxml/tinyxmlerror.cpp
diff --git a/extern/oics/tinyxmlparser.cpp b/extern/oics/tinyxml/tinyxmlparser.cpp
similarity index 100%
rename from extern/oics/tinyxmlparser.cpp
rename to extern/oics/tinyxml/tinyxmlparser.cpp
diff --git a/extern/osg-ffmpeg-videoplayer/CMakeLists.txt b/extern/osg-ffmpeg-videoplayer/CMakeLists.txt
index 8ff608bf04..3b3ff0184d 100644
--- a/extern/osg-ffmpeg-videoplayer/CMakeLists.txt
+++ b/extern/osg-ffmpeg-videoplayer/CMakeLists.txt
@@ -5,18 +5,23 @@ set(OSG_FFMPEG_VIDEOPLAYER_LIBRARY "osg-ffmpeg-videoplayer")
 set(OSG_FFMPEG_VIDEOPLAYER_SOURCE_FILES
     videoplayer.cpp
     videostate.cpp
-    videodefs.hpp
     audiodecoder.cpp
-    audiofactory.hpp
+    include/osg-ffmpeg-videoplayer/audiodecoder.hpp
+    include/osg-ffmpeg-videoplayer/audiofactory.hpp
+    include/osg-ffmpeg-videoplayer/libavformatdefines.hpp
+    include/osg-ffmpeg-videoplayer/libavutildefines.hpp
+    include/osg-ffmpeg-videoplayer/videodefs.hpp
+    include/osg-ffmpeg-videoplayer/videoplayer.hpp
+    include/osg-ffmpeg-videoplayer/videostate.hpp
 )
 
-include_directories(${FFmpeg_INCLUDE_DIRS})
 add_library(${OSG_FFMPEG_VIDEOPLAYER_LIBRARY} STATIC ${OSG_FFMPEG_VIDEOPLAYER_SOURCE_FILES})
 target_link_libraries(${OSG_FFMPEG_VIDEOPLAYER_LIBRARY} ${FFmpeg_LIBRARIES})
 target_link_libraries(${OSG_FFMPEG_VIDEOPLAYER_LIBRARY} ${OSG_LIBRARIES})
 target_link_libraries(${OSG_FFMPEG_VIDEOPLAYER_LIBRARY} SDL2::SDL2)
 
-link_directories(${CMAKE_CURRENT_BINARY_DIR})
+target_include_directories(${OSG_FFMPEG_VIDEOPLAYER_LIBRARY} PUBLIC include ${FFmpeg_INCLUDE_DIRS})
+target_include_directories(${OSG_FFMPEG_VIDEOPLAYER_LIBRARY} PRIVATE include/osg-ffmpeg-videoplayer)
 
 if (MSVC AND PRECOMPILE_HEADERS_WITH_MSVC)
     target_precompile_headers(${OSG_FFMPEG_VIDEOPLAYER_LIBRARY} PUBLIC
diff --git a/extern/osg-ffmpeg-videoplayer/audiodecoder.cpp b/extern/osg-ffmpeg-videoplayer/audiodecoder.cpp
index 9a48dff459..db3f8dc2f0 100644
--- a/extern/osg-ffmpeg-videoplayer/audiodecoder.cpp
+++ b/extern/osg-ffmpeg-videoplayer/audiodecoder.cpp
@@ -1,7 +1,5 @@
 #include "audiodecoder.hpp"
 
-#include <extern/osg-ffmpeg-videoplayer/libavutildefines.hpp>
-
 #include <algorithm>
 #include <stdexcept>
 #include <string>
@@ -24,6 +22,7 @@ extern "C"
     #include <libavutil/channel_layout.h>
 #endif
 
+#include "libavutildefines.hpp"
 #include "videostate.hpp"
 
 namespace
diff --git a/extern/osg-ffmpeg-videoplayer/audiodecoder.hpp b/extern/osg-ffmpeg-videoplayer/include/osg-ffmpeg-videoplayer/audiodecoder.hpp
similarity index 98%
rename from extern/osg-ffmpeg-videoplayer/audiodecoder.hpp
rename to extern/osg-ffmpeg-videoplayer/include/osg-ffmpeg-videoplayer/audiodecoder.hpp
index 250ba1db64..a89dca8cd7 100644
--- a/extern/osg-ffmpeg-videoplayer/audiodecoder.hpp
+++ b/extern/osg-ffmpeg-videoplayer/include/osg-ffmpeg-videoplayer/audiodecoder.hpp
@@ -6,7 +6,7 @@
 #include <new>
 #include <memory>
 
-#include <extern/osg-ffmpeg-videoplayer/libavutildefines.hpp>
+#include <osg-ffmpeg-videoplayer/libavutildefines.hpp>
 
 #if defined(_MSC_VER)
     #pragma warning (push)
diff --git a/extern/osg-ffmpeg-videoplayer/audiofactory.hpp b/extern/osg-ffmpeg-videoplayer/include/osg-ffmpeg-videoplayer/audiofactory.hpp
similarity index 100%
rename from extern/osg-ffmpeg-videoplayer/audiofactory.hpp
rename to extern/osg-ffmpeg-videoplayer/include/osg-ffmpeg-videoplayer/audiofactory.hpp
diff --git a/extern/osg-ffmpeg-videoplayer/libavformatdefines.hpp b/extern/osg-ffmpeg-videoplayer/include/osg-ffmpeg-videoplayer/libavformatdefines.hpp
similarity index 100%
rename from extern/osg-ffmpeg-videoplayer/libavformatdefines.hpp
rename to extern/osg-ffmpeg-videoplayer/include/osg-ffmpeg-videoplayer/libavformatdefines.hpp
diff --git a/extern/osg-ffmpeg-videoplayer/libavutildefines.hpp b/extern/osg-ffmpeg-videoplayer/include/osg-ffmpeg-videoplayer/libavutildefines.hpp
similarity index 100%
rename from extern/osg-ffmpeg-videoplayer/libavutildefines.hpp
rename to extern/osg-ffmpeg-videoplayer/include/osg-ffmpeg-videoplayer/libavutildefines.hpp
diff --git a/extern/osg-ffmpeg-videoplayer/videodefs.hpp b/extern/osg-ffmpeg-videoplayer/include/osg-ffmpeg-videoplayer/videodefs.hpp
similarity index 100%
rename from extern/osg-ffmpeg-videoplayer/videodefs.hpp
rename to extern/osg-ffmpeg-videoplayer/include/osg-ffmpeg-videoplayer/videodefs.hpp
diff --git a/extern/osg-ffmpeg-videoplayer/videoplayer.hpp b/extern/osg-ffmpeg-videoplayer/include/osg-ffmpeg-videoplayer/videoplayer.hpp
similarity index 100%
rename from extern/osg-ffmpeg-videoplayer/videoplayer.hpp
rename to extern/osg-ffmpeg-videoplayer/include/osg-ffmpeg-videoplayer/videoplayer.hpp
diff --git a/extern/osg-ffmpeg-videoplayer/videostate.hpp b/extern/osg-ffmpeg-videoplayer/include/osg-ffmpeg-videoplayer/videostate.hpp
similarity index 100%
rename from extern/osg-ffmpeg-videoplayer/videostate.hpp
rename to extern/osg-ffmpeg-videoplayer/include/osg-ffmpeg-videoplayer/videostate.hpp
diff --git a/extern/osgQt/CMakeLists.txt b/extern/osgQt/CMakeLists.txt
index 1cfb8230a3..3b7be3e042 100644
--- a/extern/osgQt/CMakeLists.txt
+++ b/extern/osgQt/CMakeLists.txt
@@ -3,8 +3,8 @@ set(OSGQT_LIBRARY "osgQt")
 # Sources
 
 set(SOURCE_H
-    osgQOpenGLWidget.hpp
-    CompositeOsgRenderer.hpp
+    include/osgQt/osgQOpenGLWidget.hpp
+    include/osgQt/CompositeOsgRenderer.hpp
 )
 
 qt_wrap_cpp(SOURCES_H_MOC ${SOURCE_H} )
@@ -16,9 +16,9 @@ set(OSGQT_SOURCE_FILES
 )
 
 add_library(${OSGQT_LIBRARY} STATIC ${OSGQT_SOURCE_FILES})
+target_include_directories(${OSGQT_LIBRARY} PUBLIC include)
+target_include_directories(${OSGQT_LIBRARY} PRIVATE include/osgQt)
 
 target_link_libraries(${OSGQT_LIBRARY} Qt::Core Qt::OpenGL Qt::OpenGLWidgets)
 
-link_directories(${CMAKE_CURRENT_BINARY_DIR})
-
 set(EXTERN_OSGQT_LIBRARY ${OSGQT_LIBRARY} PARENT_SCOPE)
diff --git a/extern/osgQt/CompositeOsgRenderer.hpp b/extern/osgQt/include/osgQt/CompositeOsgRenderer.hpp
similarity index 100%
rename from extern/osgQt/CompositeOsgRenderer.hpp
rename to extern/osgQt/include/osgQt/CompositeOsgRenderer.hpp
diff --git a/extern/osgQt/osgQOpenGLWidget.hpp b/extern/osgQt/include/osgQt/osgQOpenGLWidget.hpp
similarity index 100%
rename from extern/osgQt/osgQOpenGLWidget.hpp
rename to extern/osgQt/include/osgQt/osgQOpenGLWidget.hpp
diff --git a/extern/smhasher/CMakeLists.txt b/extern/smhasher/CMakeLists.txt
index ee03e6c38e..cf4208ede6 100644
--- a/extern/smhasher/CMakeLists.txt
+++ b/extern/smhasher/CMakeLists.txt
@@ -1,2 +1,3 @@
-add_library(smhasher STATIC MurmurHash3.cpp)
-target_include_directories(smhasher INTERFACE .)
+add_library(smhasher STATIC MurmurHash3.cpp include/smhasher/MurmurHash3.h)
+target_include_directories(smhasher PUBLIC include)
+target_include_directories(smhasher PRIVATE include/smhasher)
diff --git a/extern/smhasher/MurmurHash3.h b/extern/smhasher/include/smhasher/MurmurHash3.h
similarity index 100%
rename from extern/smhasher/MurmurHash3.h
rename to extern/smhasher/include/smhasher/MurmurHash3.h