diff --git a/icyc.scm b/icyc.scm
index 95ebb939..d5d0ae8a 100644
--- a/icyc.scm
+++ b/icyc.scm
@@ -36,7 +36,8 @@
             ((pair? obj)
              (when (string? (car obj))
                (display (car obj))
-               (display ": ")
+               (if (not (null? (cdr obj)))
+                   (display ": "))
                (set! obj (cdr obj)))
              (for-each
                (lambda (o)
diff --git a/runtime.c b/runtime.c
index b74b2124..f3a81dda 100644
--- a/runtime.c
+++ b/runtime.c
@@ -516,7 +516,9 @@ object Cyc_default_exception_handler(void *data, int argc, closure _,
           type_of(car(err)) == string_tag) {
         is_msg = 0;
         Cyc_display(data, car(err), stderr);
-        fprintf(stderr, ": ");
+        if (cdr(err)) {
+          fprintf(stderr, ": ");
+        }
       } else {
         Cyc_write(data, car(err), stderr);
         fprintf(stderr, " ");