diff --git a/collects/tests/typed-scheme/optimizer/run.rkt b/collects/tests/typed-scheme/optimizer/run.rkt
index e3080a9c..04c337c6 100644
--- a/collects/tests/typed-scheme/optimizer/run.rkt
+++ b/collects/tests/typed-scheme/optimizer/run.rkt
@@ -6,8 +6,7 @@
 (define (evaluator file #:optimize [optimize? #f])
   (call-with-trusted-sandbox-configuration
    (lambda ()
-     (parameterize ([current-load-relative-directory
-                     (build-path here "tests")]
+     (parameterize ([current-load-relative-directory tests-dir]
                     [sandbox-memory-limit #f] ; TR needs memory
                     [sandbox-output 'string]
                     [sandbox-namespace-specs
@@ -28,7 +27,7 @@
          out)))))
 
 (define (generate-opt-log name)
-  (parameterize ([current-load-relative-directory (build-path here "tests")]
+  (parameterize ([current-load-relative-directory tests-dir]
                  [current-command-line-arguments  '#("--log-optimizations")])
     (with-output-to-string
       (lambda ()
@@ -56,7 +55,7 @@
                  (begin (printf "~a failed: result mismatch\n\n" name)
                         #f))))))
 
-(define-runtime-path here ".")
+(define-runtime-path tests-dir "./tests")
 
 (let ((n-failures
        (if (> (vector-length (current-command-line-arguments)) 0)
@@ -64,7 +63,7 @@
                              (vector-ref (current-command-line-arguments) 0)))
                0 1)
            (for/fold ((n-failures 0))
-             ((gen (in-directory (build-path here "tests"))))
+             ((gen (in-directory tests-dir)))
              (+ n-failures (if (test gen) 0 1))))))
   (unless (= n-failures 0)
     (error (format "~a tests failed." n-failures))))