diff --git a/headers/os/codec/AdapterIO.h b/headers/os/codec/AdapterIO.h
index 82ef19b4a2..9b35956dc3 100644
--- a/headers/os/codec/AdapterIO.h
+++ b/headers/os/codec/AdapterIO.h
@@ -8,10 +8,12 @@
 
 #include <MediaIO.h>
 #include <OS.h>
-#include <RWLocker.h>
 #include <SupportDefs.h>
 
 
+class RWLocker;
+
+
 namespace BCodecKit {
 
 
diff --git a/src/kits/codec/AdapterIO.cpp b/src/kits/codec/AdapterIO.cpp
index cc419c6faa..8f60a5c114 100644
--- a/src/kits/codec/AdapterIO.cpp
+++ b/src/kits/codec/AdapterIO.cpp
@@ -8,6 +8,7 @@
 #include <AdapterIO.h>
 
 #include <MediaIO.h>
+#include <RWLocker.h>
 
 #include <string.h>