diff --git a/collects/profj/build-info.ss b/collects/profj/build-info.ss
index 46eaf55953..0a70302c06 100644
--- a/collects/profj/build-info.ss
+++ b/collects/profj/build-info.ss
@@ -1667,12 +1667,13 @@
         (let ((k (if (eq? kind 'file) 'file-not-found 'directory-not-found)))
           (raise-error k
                        (case kind
-                         ((file) (format "Required file ~a not found" (path->ext path)))
+                         ((file) (format "Required file ~a, for class or interface ~a, not found" 
+                                         (string-append (path->ext path) ".java") (path->ext path)))
                          ((dir) (format "Required directory ~a not found" (path->ext path))))
                        k src))
         (raise-error (string->symbol (car path))
                      (case kind
-                       ((file) (format "Class ~a is not known" (path->ext path)))
+                       ((file) (format "Class or interface ~a is not known" (path->ext path)))
                        ((dir) (format "Directory to search, ~a, is not known" (path->ext path))))
                      (string->symbol (car path))
                      src)))