Index: libcfa/src/concurrency/io/types.hfa
===================================================================
--- libcfa/src/concurrency/io/types.hfa	(revision 31ef26735f46b5359d660de018c9a7f84beea961)
+++ libcfa/src/concurrency/io/types.hfa	(revision e71e94afb7e0016d752678b114b94246be5a4680)
@@ -25,4 +25,5 @@
 #include "iofwd.hfa"
 #include "kernel/fwd.hfa"
+#include "limits.hfa"
 
 #if defined(CFA_HAVE_LINUX_IO_URING_H)
@@ -136,4 +137,9 @@
 
 	static inline unsigned long long ts($io_context *& this) {
+		const __u32 head = *this->cq.head;
+		const __u32 tail = *this->cq.tail;
+
+		if(head == tail) return MAX;
+
 		return this->cq.ts;
 	}
Index: libcfa/src/concurrency/ready_subqueue.hfa
===================================================================
--- libcfa/src/concurrency/ready_subqueue.hfa	(revision 31ef26735f46b5359d660de018c9a7f84beea961)
+++ libcfa/src/concurrency/ready_subqueue.hfa	(revision e71e94afb7e0016d752678b114b94246be5a4680)
@@ -3,5 +3,5 @@
 #define __CFA_NO_SCHED_STATS__
 
-#include "containers/queueLockFree.hfa"
+#include "limits.hfa"
 
 // Intrusives lanes which are used by the relaxed ready queue
@@ -32,15 +32,15 @@
 	/* paranoid */ verify( this.lock );
 	/* paranoid */ verify( node->link.next == 0p );
-	/* paranoid */ verify( node->link.ts   == -1llu  );
+	/* paranoid */ verify( node->link.ts   == MAX  );
 	/* paranoid */ verify( this.prev->link.next == 0p );
-	/* paranoid */ verify( this.prev->link.ts   == -1llu  );
+	/* paranoid */ verify( this.prev->link.ts   == MAX  );
 	if( this.anchor.next == 0p ) {
 		/* paranoid */ verify( this.anchor.next == 0p );
-		/* paranoid */ verify( this.anchor.ts   == -1llu );
+		/* paranoid */ verify( this.anchor.ts   == MAX );
 		/* paranoid */ verify( this.anchor.ts   != 0  );
 		/* paranoid */ verify( this.prev == mock_head( this ) );
 	} else {
 		/* paranoid */ verify( this.anchor.next != 0p );
-		/* paranoid */ verify( this.anchor.ts   != -1llu );
+		/* paranoid */ verify( this.anchor.ts   != MAX );
 		/* paranoid */ verify( this.anchor.ts   != 0  );
 		/* paranoid */ verify( this.prev != mock_head( this ) );
@@ -62,5 +62,5 @@
 	/* paranoid */ verify( this.lock );
 	/* paranoid */ verify( this.anchor.next != 0p );
-	/* paranoid */ verify( this.anchor.ts   != -1llu );
+	/* paranoid */ verify( this.anchor.ts   != MAX );
 	/* paranoid */ verify( this.anchor.ts   != 0  );
 
@@ -71,5 +71,5 @@
 	bool is_empty = this.anchor.next == 0p;
 	node->link.next = 0p;
-	node->link.ts   = -1llu;
+	node->link.ts   = MAX;
 	#if !defined(__CFA_NO_STATISTICS__)
 		this.cnt--;
@@ -80,5 +80,5 @@
 
 	/* paranoid */ verify( node->link.next == 0p );
-	/* paranoid */ verify( node->link.ts   == -1llu  );
+	/* paranoid */ verify( node->link.ts   == MAX  );
 	/* paranoid */ verify( node->link.ts   != 0  );
 	/* paranoid */ verify( this.anchor.ts  != 0  );