Index: src/libcfa/containers/maybe
===================================================================
--- src/libcfa/containers/maybe	(revision 79308c8e374920c0ae0843de7e5c3c35b83ff992)
+++ src/libcfa/containers/maybe	(revision 64fc0bafc25144f94bd5bbd4794fdbef138cdd9f)
@@ -18,9 +18,10 @@
 #define MAYBE_H
 
+#include <stdbool.h>
 
 // DO NOT USE DIRECTLY!
 forall(otype T)
 struct maybe {
-    _Bool has_value;
+    bool has_value;
     T value;
 };
@@ -40,5 +41,5 @@
 
 forall(otype T)
-_Bool ?!=?(result(T, E) this, zero_t);
+bool ?!=?(maybe(T) this, zero_t);
 
 forall(otype T)
@@ -49,5 +50,5 @@
 
 forall(otype T)
-_Bool has_value(maybe(T) * this);
+bool has_value(maybe(T) * this);
 
 forall(otype T)