diff --git a/include/AL/al.h b/include/AL/al.h
index 07f9ae7..c409701 100644
--- a/include/AL/al.h
+++ b/include/AL/al.h
@@ -52,7 +52,7 @@ typedef char ALboolean;
 typedef char ALchar;
 
 /** signed 8-bit 2's complement integer */
-typedef char ALbyte;
+typedef signed char ALbyte;
 
 /** unsigned 8-bit integer */
 typedef unsigned char ALubyte;
diff --git a/include/AL/alc.h b/include/AL/alc.h
index b5996ad..4e84af4 100644
--- a/include/AL/alc.h
+++ b/include/AL/alc.h
@@ -51,7 +51,7 @@ typedef char ALCboolean;
 typedef char ALCchar;
 
 /** signed 8-bit 2's complement integer */
-typedef char ALCbyte;
+typedef signed char ALCbyte;
 
 /** unsigned 8-bit integer */
 typedef unsigned char ALCubyte;