diff --git a/tests/io/test_text.py b/tests/io/test_text.py
index 501a8a2450..a29e7b37d3 100644
--- a/tests/io/test_text.py
+++ b/tests/io/test_text.py
@@ -6,6 +6,8 @@
 
 import numpy as np
 
+from io import StringIO
+
 from metpy.cbook import get_test_data
 from metpy.io import parse_wpc_surface_bulletin
 from metpy.io.text import _decode_coords
@@ -64,22 +66,36 @@ def test_parse_wpc_surface_bulletin():
     assert all(df.valid == datetime(2021, 6, 28, 18, 0, 0))
 
 
-def test_negative_lat_highres():
+def  test_negative_lat_highres():
     """Test decoding of high res coordinates with negative latitude."""
-    coord = '-4920344'
-    lon, lat = _decode_coords(coord)
-    assert lon == -34.4
-    assert lat == -49.2
+
+    from io import BytesIO
+    import shapely.geometry as sgeom
+
+    sample = BytesIO(b'''
+178 
+ASUS02 KWBC 281800
+CODSUS
+ 
+CODED SURFACE FRONTAL POSITIONS
+NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
+342 PM EDT MON JUN 28 2021
+ 
+VALID 062818Z
+HIGHS 1022 -3961069 1020 -3851069 1026 3750773 1022 4430845 1019 5520728 1018
+''')
+    df = parse_wpc_surface_bulletin(sample)
+    assert df.geometry[0] == sgeom.Point([-106.9, -39.6])
 
 
 def test_negative_lat():
     """Test decoding of coordinates with negative latitude."""
-    coord_4_digit = '-2378'
-    lon, lat = _decode_coords(coord_4_digit)
-    assert lon == -78
-    assert lat == -23
-
-    coord_5_digit = '-65134'
-    lon, lat = _decode_coords(coord_5_digit)
-    assert lon == -134
-    assert lat == -65
+
+    from io import BytesIO
+    import shapely.geometry as sgeom
+
+    sample = BytesIO(b'''12HR PROG VALID xxxxxxZ
+HIGHS -351 -3985 -4046 -38117 -7510 
+ ''')
+    df = parse_wpc_surface_bulletin(sample)
+    assert df.geometry[0] == sgeom.Point([-51, -3])