diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index 616a01772..9d35e510c 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -51,7 +51,7 @@ find_package(Freetype REQUIRED)
 include_directories(${FREETYPE_INCLUDE_DIRS})
 
 find_package(OpenAL CONFIG REQUIRED)
-include_directories(${OPENAL_INCLUDE_DIRS})
+include_directories(${OPENAL_INCLUDE_DIR})
 target_link_libraries(86Box OpenAL::OpenAL)
 
 find_package(SDL2 CONFIG REQUIRED)
diff --git a/src/sound/openal.c b/src/sound/openal.c
index 39819f591..f0d62b5b5 100644
--- a/src/sound/openal.c
+++ b/src/sound/openal.c
@@ -26,9 +26,9 @@
 # undef ALC_API
 # define AL_LIBTYPE_STATIC
 # define ALC_LIBTYPE_STATIC
-# include <AL/al.h>
-# include <AL/alc.h>
-# include <AL/alext.h>
+# include <al.h>
+# include <alc.h>
+# include <alext.h>
 #include <86box/86box.h>
 #include <86box/sound.h>
 #include <86box/midi.h>