Moved __cplusplus extern statement to include struct definitions as well.
diff --git a/include/polarssl/arc4.h b/include/polarssl/arc4.h
index 1672fa2..aa8feaa 100644
--- a/include/polarssl/arc4.h
+++ b/include/polarssl/arc4.h
@@ -35,6 +35,10 @@
 // Regular implementation
 //
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 /**
  * \brief          ARC4 context structure
  */
@@ -46,10 +50,6 @@
 }
 arc4_context;
 
-#ifdef __cplusplus
-extern "C" {
-#endif
-
 /**
  * \brief          ARC4 key schedule
  *