diff --git a/simgear/sound/soundmgr_openal.hxx b/simgear/sound/soundmgr_openal.hxx
index 2c40eeca..84c33502 100644
--- a/simgear/sound/soundmgr_openal.hxx
+++ b/simgear/sound/soundmgr_openal.hxx
@@ -45,9 +45,11 @@
 # define AL_ILLEGAL_ENUM AL_INVALID_ENUM
 # define AL_ILLEGAL_COMMAND AL_INVALID_OPERATION
 # include <OpenAL/al.h>
+# include <OpenAL/alc.h>
 # include <OpenAL/alut.h>
 #else
 # include <AL/al.h>
+# include <AL/alc.h>
 # include <AL/alut.h>
 #endif