diff --git a/bindings/guile/test/test-engine-extras.scm b/bindings/guile/test/test-engine-extras.scm
index 336c2103c9..8e3087efa6 100644
--- a/bindings/guile/test/test-engine-extras.scm
+++ b/bindings/guile/test/test-engine-extras.scm
@@ -21,6 +21,7 @@
 
 (use-modules (gnucash app-utils))
 (use-modules (gnucash engine))
+(use-modules (gnucash utilities))
 (use-modules (srfi srfi-1))
 (use-modules (sw_app_utils))
 (use-modules (sw_engine))
@@ -342,12 +343,8 @@
 
 (define (env-create-account-structure-alist env account-structure)
   (let ((accounts (env-create-account-structure env account-structure)))
-    (define (flatten l)
-      (if (null? l) '()
-	  (if (not (pair? l)) (list l)
-	      (append (flatten (car l)) (flatten (cdr l))))))
     (map (lambda (acct) (cons (xaccAccountGetName acct) acct))
-	 (flatten accounts))))
+	 (gnc:list-flatten accounts))))
 
 (define (env-expense-account-structure env)
   (env-create-account-structure
diff --git a/gnucash/report/reports/standard/test/test-standard-category-report.scm b/gnucash/report/reports/standard/test/test-standard-category-report.scm
index f2e380d039..c700e1971e 100644
--- a/gnucash/report/reports/standard/test/test-standard-category-report.scm
+++ b/gnucash/report/reports/standard/test/test-standard-category-report.scm
@@ -205,15 +205,6 @@
     (test-end "multiplier test"))
   (teardown))
 
-(define (list-leaves list)
-  (if (not (pair? list))
-      (cons list '())
-      (fold (lambda (next acc)
-	      (append (list-leaves next)
-		      acc))
-	    '()
-	    list)))
-
 (define (multi-acct-test expense-report-uuid)
   (let* ((expense-options (gnc:make-report-options expense-report-uuid))
          (env (create-test-env))
@@ -223,7 +214,7 @@
                           (list "Assets"
                                 (list (cons 'type ACCT-TYPE-ASSET))
                                 (list "Bank"))))
-         (leaf-expense-accounts (list-leaves expense-accounts))
+         (leaf-expense-accounts (gnc:list-flatten expense-accounts))
          (bank-account (car (car (cdr asset-accounts)))))
     (for-each (lambda (expense-account)
                 (env-create-daily-transactions env