diff --git a/tests/tbf/tb0158.pp b/tests/tbf/tb0158.pp
new file mode 100644
index 0000000000..64e0aa30b9
--- /dev/null
+++ b/tests/tbf/tb0158.pp
@@ -0,0 +1,4 @@
+uses ub0158a;
+
+begin
+end.
diff --git a/tests/tbf/ub0158a.pp b/tests/tbf/ub0158a.pp
new file mode 100644
index 0000000000..deeb538bc1
--- /dev/null
+++ b/tests/tbf/ub0158a.pp
@@ -0,0 +1,13 @@
+unit ub0158a;
+
+interface
+
+uses ub0158b;
+
+implementation
+
+{ should give "duplicate identifier error", because already used in the }
+{ interface                                                             }
+uses ub0158b;
+
+end.
diff --git a/tests/tbf/ub0158b.pp b/tests/tbf/ub0158b.pp
new file mode 100644
index 0000000000..d789c5d97e
--- /dev/null
+++ b/tests/tbf/ub0158b.pp
@@ -0,0 +1,7 @@
+unit ub0158b;
+
+interface
+
+implementation
+
+end.