Index: src/Concurrency/Waitfor.cc
===================================================================
--- src/Concurrency/Waitfor.cc	(revision 8f98b782aebdb59bd3ba7eae826ba604a978928a)
+++ src/Concurrency/Waitfor.cc	(revision b18830e160544a32e0d1b1ea1100232bf1c4545d)
@@ -484,5 +484,5 @@
 				new CaseStmt(
 					noLabels,
-					new ConstantExpr( Constant::from_ulong( i++ ) ),
+					new ConstantExpr( Constant::from_int( -2 ) ),
 					{
 						waitfor->timeout.statement,
@@ -501,5 +501,5 @@
 				new CaseStmt(
 					noLabels,
-					new ConstantExpr( Constant::from_ulong( i++ ) ),
+					new ConstantExpr( Constant::from_int( -1 ) ),
 					{
 						waitfor->orelse.statement,