diff --git a/elaborate.cc b/elaborate.cc
index 1ec20a887..03e33aa35 100644
--- a/elaborate.cc
+++ b/elaborate.cc
@@ -2741,7 +2741,7 @@ NetProc* PDelayStatement::elaborate(Design*des, NetScope*scope) const
 		  return new NetPDelay(tmp->value().as_ulong64(),
 				       statement_->elaborate(des, scope));
 	    else
-		  return new NetPDelay(tmp->value().as_ulong(), 0);
+		  return new NetPDelay(tmp->value().as_ulong64(), 0);
 
 	    delete dex;
 
diff --git a/vvp/opcodes.txt b/vvp/opcodes.txt
index db3de0c4e..dc24887e8 100644
--- a/vvp/opcodes.txt
+++ b/vvp/opcodes.txt
@@ -280,14 +280,17 @@ will be deactivated. For a full deactivation the <base> is 0 and
 
 The same as %deassign above except this is used for real variables.
 
-* %delay <delay>
+* %delay <low>, <high>
 
 This opcode pauses the thread, and causes it to be rescheduled for a
-time in the future. The <amount> is the number of the ticks in the
+time in the future. The amount is the number of the ticks in the
 future to reschedule, and is >= 0. If the %delay is zero, then the
 thread yields the processor for another thread, but will be resumed in
 the current time step.
 
+The delay amount is given as 2 32bit numbers, so that 64bit times may
+be represented.
+
 * %delayx <idx>
 
 This is similar to the %delay opcode, except that the parameter