Index: uspace/lib/c/generic/fibril.c
===================================================================
--- uspace/lib/c/generic/fibril.c	(revision 3e20fd481daa3a3499b65a8cbbe231b962f35ad3)
+++ uspace/lib/c/generic/fibril.c	(revision 7f122e3870e33f0d019db459612b5911ef5f0d1d)
@@ -275,4 +275,6 @@
 	fibril->func = func;
 	fibril->arg = arg;
+
+	fibril->waits_for = NULL;
 	
 	context_save(&fibril->ctx);
Index: uspace/lib/c/include/fibril.h
===================================================================
--- uspace/lib/c/include/fibril.h	(revision 3e20fd481daa3a3499b65a8cbbe231b962f35ad3)
+++ uspace/lib/c/include/fibril.h	(revision 7f122e3870e33f0d019db459612b5911ef5f0d1d)
@@ -48,4 +48,10 @@
 #define FIBRIL_WRITER      2
 
+struct fibril;
+
+typedef struct {
+	struct fibril *owned_by;
+} fibril_owner_info_t;
+
 typedef enum {
 	FIBRIL_PREEMPT,
@@ -68,4 +74,6 @@
 	int retval;
 	int flags;
+
+	fibril_owner_info_t *waits_for;
 } fibril_t;
 
Index: uspace/lib/c/include/fibril_synch.h
===================================================================
--- uspace/lib/c/include/fibril_synch.h	(revision 3e20fd481daa3a3499b65a8cbbe231b962f35ad3)
+++ uspace/lib/c/include/fibril_synch.h	(revision 7f122e3870e33f0d019db459612b5911ef5f0d1d)
@@ -41,8 +41,4 @@
 #include <libarch/tls.h>
 #include <sys/time.h>
-
-typedef struct {
-	fibril_t *owned_by;
-} fibril_owner_info_t;
 
 typedef struct {