diff --git a/test-suite/lib.scm b/test-suite/lib.scm
index 87ab54da8..bcf6bd400 100644
--- a/test-suite/lib.scm
+++ b/test-suite/lib.scm
@@ -16,7 +16,8 @@
 ;;;; the Free Software Foundation, Inc., 59 Temple Place, Suite 330,
 ;;;; Boston, MA 02111-1307 USA
 
-(define-module (test-suite lib))
+(define-module (test-suite lib)
+  #:use-module (test-suite paths))
 
 (export
 
@@ -38,7 +39,10 @@
  make-log-reporter 
  full-reporter
  user-reporter
- format-test-name)
+ format-test-name
+
+ ;; Finding test input files.
+ data-file)
 
 
 ;;;; If you're using Emacs's Scheme mode:
@@ -402,3 +406,14 @@
 
 (define (pass-if name condition)
   ((if condition pass fail) name))
+
+
+;;;; Helping test cases find their files
+
+;;; Returns FILENAME, relative to the directory the test suite data
+;;; files were installed in, and makes sure the file exists.
+(define (data-file filename)
+  (let ((f (in-vicinity datadir filename)))
+    (or (file-exists? f)
+	(error "Test suite data file does not exist: " f))
+    f))