Index: libcfa/src/concurrency/kernel/startup.cfa
===================================================================
--- libcfa/src/concurrency/kernel/startup.cfa	(revision 4d865ca729efe90d431f261b8f8f05af3958c212)
+++ libcfa/src/concurrency/kernel/startup.cfa	(revision ef94ae7a9002590fa21cae730af5d99e56d616c0)
@@ -484,5 +484,5 @@
 	self_mon_p = &self_mon;
 	link.next = 0p;
-	link.ts   = 0;
+	link.ts   = -1llu;
 	preferred = -1u;
 	last_proc = 0p;
Index: libcfa/src/concurrency/ready_queue.cfa
===================================================================
--- libcfa/src/concurrency/ready_queue.cfa	(revision 4d865ca729efe90d431f261b8f8f05af3958c212)
+++ libcfa/src/concurrency/ready_queue.cfa	(revision ef94ae7a9002590fa21cae730af5d99e56d616c0)
@@ -679,9 +679,9 @@
 					if(is_empty(sl)) {
 						assert( sl.anchor.next == 0p );
-						assert( sl.anchor.ts   == 0  );
+						assert( sl.anchor.ts   == -1llu );
 						assert( mock_head(sl)  == sl.prev );
 					} else {
 						assert( sl.anchor.next != 0p );
-						assert( sl.anchor.ts   != 0  );
+						assert( sl.anchor.ts   != -1llu );
 						assert( mock_head(sl)  != sl.prev );
 					}
@@ -733,6 +733,7 @@
 		lanes.tscs = alloc(lanes.count, lanes.tscs`realloc);
 		for(i; lanes.count) {
-			unsigned long long tsc = ts(lanes.data[i]);
-			lanes.tscs[i].tv = tsc != 0 ? tsc : rdtscl();
+			unsigned long long tsc1 = ts(lanes.data[i]);
+			unsigned long long tsc2 = rdtscl()
+			lanes.tscs[i].tv = min(tsc1, tsc2);
 		}
 	#endif
Index: libcfa/src/concurrency/ready_subqueue.hfa
===================================================================
--- libcfa/src/concurrency/ready_subqueue.hfa	(revision 4d865ca729efe90d431f261b8f8f05af3958c212)
+++ libcfa/src/concurrency/ready_subqueue.hfa	(revision ef94ae7a9002590fa21cae730af5d99e56d616c0)
@@ -32,5 +32,5 @@
 	this.prev = mock_head(this);
 	this.anchor.next = 0p;
-	this.anchor.ts   = 0;
+	this.anchor.ts   = -1llu;
 	#if !defined(__CFA_NO_STATISTICS__)
 		this.cnt  = 0;
@@ -44,5 +44,5 @@
 	/* paranoid */ verify( &mock_head(this)->link.ts   == &this.anchor.ts   );
 	/* paranoid */ verify( mock_head(this)->link.next == 0p );
-	/* paranoid */ verify( mock_head(this)->link.ts   == 0  );
+	/* paranoid */ verify( mock_head(this)->link.ts   == -1llu  );
 	/* paranoid */ verify( mock_head(this) == this.prev );
 	/* paranoid */ verify( __alignof__(__intrusive_lane_t) == 128 );
@@ -55,5 +55,5 @@
 	// Make sure the list is empty
 	/* paranoid */ verify( this.anchor.next == 0p );
-	/* paranoid */ verify( this.anchor.ts   == 0  );
+	/* paranoid */ verify( this.anchor.ts   == -1llu );
 	/* paranoid */ verify( mock_head(this)  == this.prev );
 }
@@ -64,13 +64,15 @@
 	/* paranoid */ verify( this.lock );
 	/* paranoid */ verify( node->link.next == 0p );
-	/* paranoid */ verify( node->link.ts   == 0  );
+	/* paranoid */ verify( node->link.ts   == -1llu  );
 	/* paranoid */ verify( this.prev->link.next == 0p );
-	/* paranoid */ verify( this.prev->link.ts   == 0  );
+	/* paranoid */ verify( this.prev->link.ts   == -1llu  );
 	if( this.anchor.next == 0p ) {
 		/* paranoid */ verify( this.anchor.next == 0p );
-		/* paranoid */ verify( this.anchor.ts   == 0  );
+		/* paranoid */ verify( this.anchor.ts   == -1llu );
+		/* 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   != 0  );
 		/* paranoid */ verify( this.prev != mock_head( this ) );
@@ -92,4 +94,5 @@
 	/* paranoid */ verify( this.lock );
 	/* paranoid */ verify( this.anchor.next != 0p );
+	/* paranoid */ verify( this.anchor.ts   != -1llu );
 	/* paranoid */ verify( this.anchor.ts   != 0  );
 
@@ -99,7 +102,7 @@
 	this.anchor.next = node->link.next;
 	this.anchor.ts   = node->link.ts;
-	bool is_empty = this.anchor.ts == 0;
+	bool is_empty = this.anchor.next == 0p;
 	node->link.next = 0p;
-	node->link.ts   = 0;
+	node->link.ts   = -1llu;
 	#if !defined(__CFA_NO_STATISTICS__)
 		this.cnt--;
@@ -110,5 +113,7 @@
 
 	/* paranoid */ verify( node->link.next == 0p );
-	/* paranoid */ verify( node->link.ts   == 0  );
+	/* paranoid */ verify( node->link.ts   == -1llu  );
+	/* paranoid */ verify( node->link.ts   != 0  );
+	/* paranoid */ verify( this.anchor.ts  != 0  );
 	return [node, ts];
 }
@@ -116,5 +121,5 @@
 // Check whether or not list is empty
 static inline bool is_empty(__intrusive_lane_t & this) {
-	return this.anchor.ts == 0;
+	return this.anchor.next == 0p;
 }
 
@@ -122,4 +127,5 @@
 static inline unsigned long long ts(__intrusive_lane_t & this) {
 	// Cannot verify here since it may not be locked
+	/* paranoid */ verify(this.anchor.ts != 0);
 	return this.anchor.ts;
 }
Index: libcfa/src/concurrency/thread.cfa
===================================================================
--- libcfa/src/concurrency/thread.cfa	(revision 4d865ca729efe90d431f261b8f8f05af3958c212)
+++ libcfa/src/concurrency/thread.cfa	(revision ef94ae7a9002590fa21cae730af5d99e56d616c0)
@@ -40,5 +40,5 @@
 	curr_cluster = &cl;
 	link.next = 0p;
-	link.ts   = 0;
+	link.ts   = -1llu;
 	preferred = -1u;
 	last_proc = 0p;