diff --git a/tests/test_extractres.py b/tests/test_extractres.py
index 8842497..67b3a31 100644
--- a/tests/test_extractres.py
+++ b/tests/test_extractres.py
@@ -41,17 +41,17 @@ def test_extractres(
         regenerate_input,
         regenerate_expected,
     )
-    compare_text_files(
+    assert compare_text_files(
         capsys,
         datafiles / "ISO-8859-1Encoding.enc",
         datafiles / "ISO-8859-1Encoding-expected.enc",
     )
-    compare_text_files(
+    assert compare_text_files(
         capsys,
         datafiles / "a2ps-a2ps-hdr2.02.ps",
         datafiles / "a2ps-a2ps-hdr2.02-expected.ps",
     )
-    compare_text_files(
+    assert compare_text_files(
         capsys,
         datafiles / "a2ps-black+white-Prolog2.01.ps",
         datafiles / "a2ps-black+white-Prolog2.01-expected.ps",