diff --git a/timer.lisp b/timer.lisp
index 568f868..49d8675 100644
--- a/timer.lisp
+++ b/timer.lisp
@@ -30,11 +30,8 @@
     (if (numberp time)
         ;; time is not bogus, make a timeval struct and add the event to the
         ;; loop for delayed processing.
-        (multiple-value-bind (time-sec time-usec) (split-usec-time time)
-          (make-foreign-type (time-c (le::cffi-type le::timeval))
-                             (('le::tv-sec time-sec)
-                              ('le::tv-usec time-usec))
-            (le:event-add ev time-c)))
+        (with-struct-timeval time-c time
+          (le:event-add ev time-c))
         ;; there was no time specified (or it wasn't a number), so fire up the
         ;; event to be processed with no delay
         (le:event-active ev 0 0))))
diff --git a/util.lisp b/util.lisp
index 24f302b..6ab8dfc 100644
--- a/util.lisp
+++ b/util.lisp
@@ -47,6 +47,7 @@
            #:clear-pointer-data
            #:free-pointer-data
 
+           #:with-struct-timeval
            #:split-usec-time
 
            #:append-array
@@ -234,6 +235,14 @@
         (when (cffi:pointerp pointer)
           (cffi:foreign-free pointer))))))
 
+(defmacro with-struct-timeval (var seconds &rest body)
+  "Convert seconds to a valid struct timeval C data type."
+  `(multiple-value-bind (time-sec time-usec) (split-usec-time ,seconds)
+     (make-foreign-type (,var (le::cffi-type le::timeval))
+                        (('le::tv-sec time-sec)
+                         ('le::tv-usec time-usec))
+       ,@body)))
+
 (defun split-usec-time (time-s)
   "Given a second value, ie 3.67, return the number of seconds as the first
    value and the number of usecs for the second value."