diff --git a/scsh/event.scm b/scsh/event.scm
index 8a9c855..507dd2e 100644
--- a/scsh/event.scm
+++ b/scsh/event.scm
@@ -35,7 +35,7 @@
 ;Initialize the system.
 (define (install-event-handlers!)
   (let loop ((count 0))
-    (if (< count (number-of-interrupts))  
+    (if (< count number-of-interrupts)  
 	(begin 
 	;we're not interested in the setter-function here:
 	  (low-interrupt-register  
diff --git a/scsh/low-interrupt.scm b/scsh/low-interrupt.scm
index e4a57fa..c05b99f 100644
--- a/scsh/low-interrupt.scm
+++ b/scsh/low-interrupt.scm
@@ -23,22 +23,22 @@
    xfsz
    ))
 
-;;; TODO: don't make this a thunk
-(define (number-of-interrupts)
+
+(define number-of-interrupts
   low-interrupt-count)
 
 (define low-interrupt-handlers-vector 
-  (make-vector (number-of-interrupts) '()))
+  (make-vector number-of-interrupts '()))
 
 
 (define (low-interrupt-handler-ref interrupt)
-  (if (or (< interrupt 0) (>= interrupt (number-of-interrupts)))
+  (if (or (< interrupt 0) (>= interrupt number-of-interrupts))
       (error "ill signum in low-interrupt-handler-ref" interrupt)
       (vector-ref low-interrupt-handlers-vector interrupt)))
 
 
 (define (set-low-interrupt-handler! int handler)
-  (if (or (< int 0) (>= int (number-of-interrupts)))
+  (if (or (< int 0) (>= int number-of-interrupts))
       (error "ill signum in set-low-interrupt-handler!" int)
       (vector-set! low-interrupt-handlers-vector int handler)))