diff --git a/moo/kernel/test-004.moo b/moo/kernel/test-004.moo
index 44a2d0e..2b76f2b 100644
--- a/moo/kernel/test-004.moo
+++ b/moo/kernel/test-004.moo
@@ -20,7 +20,7 @@ class MyObject(Object)
 		       s signal.
 		       Processor activeProcess terminate.
 		       self.t1 := self.t1 + 20 ] fork.
-		s wait.	
+		s wait.
 		^self.t1
 	}
 
@@ -38,14 +38,15 @@ class MyObject(Object)
 		sg addSemaphore: s3.
 
 		Processor signal: s1 onInput: 0.
-		Processor signal: s2 onInput: 0. ## this should raise an exception.
-		Processor signal: s3 onInput: 0.
+		##Processor signal: s2 onInput: 0. ## this should raise an exception.
+		##Processor signal: s3 onInput: 0.
 
 		[ sg wait. ] fork.
 		[ sg wait. ] fork.
 		[ sg wait. ] fork.
 
 		sg wait.
+sg removeSemaphore: s1.
 	}
 
 	method(#class) main
diff --git a/moo/lib/exec.c b/moo/lib/exec.c
index e86cd0f..a8e3dd3 100644
--- a/moo/lib/exec.c
+++ b/moo/lib/exec.c
@@ -744,6 +744,7 @@ static moo_oop_process_t signal_semaphore (moo_t* moo, moo_oop_semaphore_t sem)
 			MOO_ASSERT (moo, MOO_OOP_TO_SMOOI(proc->sp) < (moo_ooi_t)(MOO_OBJ_GET_SIZE(proc) - MOO_PROCESS_NAMED_INSTVARS));
 			proc->slot[MOO_OOP_TO_SMOOI(proc->sp)] = (moo_oop_t)sem;
 
+			if (MOO_OOP_TO_SMOOI(sem->io_index) >= 0) moo->sem_io_wait_count--;
 			return proc;
 		}
 	}
@@ -5052,7 +5053,6 @@ switch_to_next:
 
 static MOO_INLINE int do_return (moo_t* moo, moo_oob_t bcode, moo_oop_t return_value)
 {
-
 #if 0
 	/* put the instruction pointer back to the return
 	 * instruction (RETURN_RECEIVER or RETURN_RECEIVER)