diff --git a/tests/data/SourceSansPro-Regular.otf b/tests/data/SourceSansPro-Regular.otf
new file mode 100644
index 0000000..279e691
Binary files /dev/null and b/tests/data/SourceSansPro-Regular.otf differ
diff --git a/tests/test_uharfbuzz.py b/tests/test_uharfbuzz.py
index 0b16457..f5b47c5 100644
--- a/tests/test_uharfbuzz.py
+++ b/tests/test_uharfbuzz.py
@@ -8,6 +8,7 @@
 TESTDATA = Path(__file__).parent / "data"
 ADOBE_BLANK_TTF_PATH = TESTDATA / "AdobeBlank.subset.ttf"
 OPEN_SANS_TTF_PATH = TESTDATA / "OpenSans.subset.ttf"
+SOURCE_SANS_PRO_OTF_PATH = TESTDATA / "SourceSansPro-Regular.otf"
 MUTATOR_SANS_TTF_PATH = TESTDATA / "MutatorSans-VF.subset.ttf"
 SPARSE_FONT_TTF_PATH = TESTDATA / "SparseFont.ttf"
 MATH_FONT_TTF_PATH = TESTDATA / "STIXTwoMath-Regular.ttf"
@@ -34,6 +35,15 @@ def blankfont():
     return font
 
 
+@pytest.fixture
+def sourcesance():
+    """Returns the full Source sans Pro Regular font."""
+    blob = hb.Blob.from_file_path(SOURCE_SANS_PRO_OTF_PATH)
+    face = hb.Face(blob)
+    font = hb.Font(face)
+    return font
+
+
 @pytest.fixture
 def opensans():
     """Return a subset of OpenSans.ttf containing the following glyphs/characters:
@@ -872,6 +882,14 @@ def test_ot_layout_script_get_language_tags(self, blankfont):
         assert tags == []
 
 
+class TestGetAlternates:
+    def test_ot_layout_lookup_get_glyph_alternates(self, sourcesance):
+        alternate_glyphs = hb.ot_layout_lookup_get_glyph_alternates(
+            sourcesance.face, 1, 1091
+        )
+        assert alternate_glyphs == [1549, 1620, 1606, 1578, 1592, 1103, 1115]
+
+
 class TestOTMath:
     def test_ot_math_has_data(self, mathfont):
         assert hb.ot_math_has_data(mathfont.face)