diff --git a/private/format-utils.rkt b/private/format-utils.rkt
index 9dc2077..c92ec04 100644
--- a/private/format-utils.rkt
+++ b/private/format-utils.rkt
@@ -75,7 +75,6 @@
 (define (make-irrelevant? lexer f submods)
   (define s (mutable-set))
   (define-values (for-lex for-str) (replicate-file-port f (current-input-port)))
-  (port-count-lines! for-lex)
   (define str (apply vector (string->list (port->string for-str))))
   (define init-offset (- (string-length (file->string f))
                          (vector-length str)))
@@ -163,19 +162,20 @@
 
 (module+ test
   (define-runtime-path path2 "../tests/prog.rkt")
-  (test-begin
-   (define f (path->string (simplify-path path2)))
-   (test-files! f)
-   (define coverage (hash-ref (get-test-coverage) f))
-   (define covered? (make-covered? coverage f))
-   (check-equal? (covered? 14) 'irrelevant)
-   (check-equal? (covered? 14 #:byte? #t) 'irrelevant)
-   (check-equal? (covered? 17) 'irrelevant)
-   (check-equal? (covered? 28) 'irrelevant)
-   (check-equal? (covered? 35) 'covered)
-   (check-equal? (covered? 50) 'uncovered)
-   (check-equal? (covered? 51 #:byte? #t) 'uncovered)
-   (check-equal? (covered? 52) 'irrelevant)
-   (check-equal? (covered? 53) 'irrelevant)
-   (check-equal? (covered? 54) 'irrelevant)
-   (clear-coverage!)))
+  (parameterize ([irrelevant-submodules #f])
+    (test-begin
+     (define f (path->string (simplify-path path2)))
+     (test-files! f)
+     (define coverage (hash-ref (get-test-coverage) f))
+     (define covered? (make-covered? coverage f))
+     (check-equal? (covered? 14) 'irrelevant)
+     (check-equal? (covered? 14 #:byte? #t) 'irrelevant)
+     (check-equal? (covered? 17) 'irrelevant)
+     (check-equal? (covered? 28) 'irrelevant)
+     (check-equal? (covered? 35) 'covered)
+     (check-equal? (covered? 50) 'uncovered)
+     (check-equal? (covered? 51 #:byte? #t) 'uncovered)
+     (check-equal? (covered? 52) 'irrelevant)
+     (check-equal? (covered? 53) 'irrelevant)
+     (check-equal? (covered? 54) 'irrelevant)
+     (clear-coverage!))))