Index: uspace/lib/c/include/adt/circ_buf.h
===================================================================
--- uspace/lib/c/include/adt/circ_buf.h	(revision 38d150e6238ab44c861f6486e46454e07caeb0f0)
+++ uspace/lib/c/include/adt/circ_buf.h	(revision a0a9cc249adce31c755defdb6b74a991ebbf55ea)
@@ -36,4 +36,5 @@
 #define LIBC_CIRC_BUF_H_
 
+#include <errno.h>
 #include <stddef.h>
 
@@ -57,6 +58,6 @@
 extern size_t circ_buf_nfree(circ_buf_t *);
 extern size_t circ_buf_nused(circ_buf_t *);
-extern int circ_buf_push(circ_buf_t *, const void *);
-extern int circ_buf_pop(circ_buf_t *, void *);
+extern errno_t circ_buf_push(circ_buf_t *, const void *);
+extern errno_t circ_buf_pop(circ_buf_t *, void *);
 
 #endif
Index: uspace/lib/c/include/adt/odict.h
===================================================================
--- uspace/lib/c/include/adt/odict.h	(revision 38d150e6238ab44c861f6486e46454e07caeb0f0)
+++ uspace/lib/c/include/adt/odict.h	(revision a0a9cc249adce31c755defdb6b74a991ebbf55ea)
@@ -36,4 +36,5 @@
 #define LIBC_ODICT_H_
 
+#include <errno.h>
 #include <stdbool.h>
 #include <stddef.h>
@@ -61,5 +62,5 @@
 extern odlink_t *odict_find_leq(odict_t *, void *, odlink_t *);
 extern odlink_t *odict_find_lt(odict_t *, void *, odlink_t *);
-extern int odict_validate(odict_t *);
+extern errno_t odict_validate(odict_t *);
 
 #endif