diff --git a/README.md b/README.md
index f581a74f..ef094e8c 100644
--- a/README.md
+++ b/README.md
@@ -60,3 +60,5 @@ openaddr-process-one --skip-preview --layer addresses --layersource state exampl
 ```
 
 Review https://github.com/openaddresses/openaddresses/blob/master/CONTRIBUTING.md for input json syntax.
+
+Supported conform formats include `shapefile`, `geojson`, `csv`, `xml`, `gdb`, and `gpkg`.
diff --git a/openaddr/conform.py b/openaddr/conform.py
index a25739e9..25e123a0 100644
--- a/openaddr/conform.py
+++ b/openaddr/conform.py
@@ -404,6 +404,28 @@ def find_source_path(data_source, source_paths):
                     return c
             _L.warning("Source names file %s but could not find it", source_file_name)
             return None
+    elif format_string == "gpkg":
+        candidates = []
+        for fn in source_paths:
+            basename, ext = os.path.splitext(fn)
+            if ext.lower() == ".gpkg":
+                candidates.append(fn)
+        if len(candidates) == 0:
+            _L.warning("No GPKG found in %s", source_paths)
+            return None
+        elif len(candidates) == 1:
+            _L.debug("Selected %s for source", candidates[0])
+            return candidates[0]
+        else:
+            if "file" not in conform:
+                _L.warning("Multiple GPKGs found, but source has no file attribute.")
+                return None
+            source_file_name = conform["file"]
+            for c in candidates:
+                if source_file_name == os.path.basename(c):
+                    return c
+            _L.warning("Source names file %s but could not find it", source_file_name)
+            return None
     elif format_string == "xml":
         # Return file if it's specified, else return the first .gml file we find
         if "file" in conform:
@@ -425,7 +447,7 @@ def find_source_path(data_source, source_paths):
         return None
 
 class ConvertToGeojsonTask(object):
-    known_types = ('.shp', '.json', '.csv', '.kml', '.gdb')
+    known_types = ('.shp', '.json', '.csv', '.kml', '.gdb', '.gpkg')
 
     def convert(self, source_config, source_paths, workdir):
         "Convert a list of source_paths and write results in workdir"
@@ -1151,7 +1173,7 @@ def extract_to_source_csv(source_config, source_path, extract_path):
     format_string = source_config.data_source["conform"]['format']
     protocol_string = source_config.data_source['protocol']
 
-    if format_string in ("shapefile", "xml", "gdb"):
+    if format_string in ("shapefile", "xml", "gdb", "gpkg"):
         ogr_source_path = normalize_ogr_filename_case(source_path)
         ogr_source_to_csv(source_config, ogr_source_path, extract_path)
     elif format_string == "csv":
@@ -1194,7 +1216,7 @@ def conform_cli(source_config, source_path, dest_path):
 
     format_string = source_config.data_source["conform"].get('format')
 
-    if not format_string in ["shapefile", "geojson", "csv", "xml", "gdb"]:
+    if not format_string in ["shapefile", "geojson", "csv", "xml", "gdb", "gpkg"]:
         _L.warning("Skipping file with unknown conform: %s", source_path)
         return 1
 
diff --git a/openaddr/tests/conform.py b/openaddr/tests/conform.py
index 74275248..f35ef831 100644
--- a/openaddr/tests/conform.py
+++ b/openaddr/tests/conform.py
@@ -1776,6 +1776,36 @@ def test_lake_man_gdb(self):
             self.assertEqual(rows[5]['properties']['number'], '5115')
             self.assertEqual(rows[5]['properties']['street'], 'OLD MILL RD')
 
+    def test_lake_man_gpkg(self):
+        with open(os.path.join(self.conforms_dir, "lake-man-gpkg.json")) as file:
+            source_config = SourceConfig(json.load(file), "addresses", "default")
+        source_path = os.path.join(self.conforms_dir, "lake-man.gpkg")
+        dest_path = os.path.join(self.testdir, 'lake-man-gpkg-conformed.csv')
+
+        rc = conform_cli(source_config, source_path, dest_path)
+        self.assertEqual(0, rc)
+
+        with open(dest_path) as fp:
+            rows = list(map(json.loads, list(fp)))
+
+            self.assertEqual('Point', rows[0]['geometry']['type'])
+            self.assertAlmostEqual(-122.2592497, rows[0]['geometry']['coordinates'][0], places=4)
+            self.assertAlmostEqual(37.8026126, rows[0]['geometry']['coordinates'][1], places=4)
+
+            self.assertEqual(6, len(rows))
+            self.assertEqual(rows[0]['properties']['number'], '5115')
+            self.assertEqual(rows[0]['properties']['street'], 'FRUITED PLAINS LN')
+            self.assertEqual(rows[1]['properties']['number'], '5121')
+            self.assertEqual(rows[1]['properties']['street'], 'FRUITED PLAINS LN')
+            self.assertEqual(rows[2]['properties']['number'], '5133')
+            self.assertEqual(rows[2]['properties']['street'], 'FRUITED PLAINS LN')
+            self.assertEqual(rows[3]['properties']['number'], '5126')
+            self.assertEqual(rows[3]['properties']['street'], 'FRUITED PLAINS LN')
+            self.assertEqual(rows[4]['properties']['number'], '5120')
+            self.assertEqual(rows[4]['properties']['street'], 'FRUITED PLAINS LN')
+            self.assertEqual(rows[5]['properties']['number'], '5115')
+            self.assertEqual(rows[5]['properties']['street'], 'OLD MILL RD')
+
     def test_lake_man_split(self):
         rc, dest_path = self._run_conform_on_source('lake-man-split', 'shp')
         self.assertEqual(0, rc)
@@ -2309,8 +2339,8 @@ def test_srs(self):
         self.assertEqual(r[0], u'n,s,{GEOM_FIELDNAME}'.format(**globals()))
 
         r = r[1].split(',')
-        self.assertEquals(r[0], '3203')
-        self.assertEquals(r[1], 'SE WOODSTOCK BLVD')
+        self.assertEqual(r[0], '3203')
+        self.assertEqual(r[1], 'SE WOODSTOCK BLVD')
 
         x,y = wkt_pt(r[2])
         self.assertAlmostEqual(-122.630842186651, x, places=4)
diff --git a/openaddr/tests/conforms/lake-man-gml.gfs b/openaddr/tests/conforms/lake-man-gml.gfs
new file mode 100644
index 00000000..485d1ae9
--- /dev/null
+++ b/openaddr/tests/conforms/lake-man-gml.gfs
@@ -0,0 +1,101 @@
+<GMLFeatureClassList>
+  <GMLFeatureClass>
+    <Name>lake_man</Name>
+    <ElementPath>lake_man</ElementPath>
+    <GeometryName>geometryProperty</GeometryName>
+    <GeometryElementPath>geometryProperty</GeometryElementPath>
+    <!--POINT-->
+    <GeometryType>1</GeometryType>
+    <DatasetSpecificInfo>
+      <FeatureCount>6</FeatureCount>
+      <ExtentXMin>-122.25925</ExtentXMin>
+      <ExtentXMax>-122.25672</ExtentXMax>
+      <ExtentYMin>37.80071</ExtentYMin>
+      <ExtentYMax>37.80436</ExtentYMax>
+    </DatasetSpecificInfo>
+    <PropertyDefn>
+      <Name>MSTRID</Name>
+      <ElementPath>MSTRID</ElementPath>
+      <Type>Integer</Type>
+    </PropertyDefn>
+    <PropertyDefn>
+      <Name>CATEGORY</Name>
+      <ElementPath>CATEGORY</ElementPath>
+      <Type>String</Type>
+      <Width>7</Width>
+    </PropertyDefn>
+    <PropertyDefn>
+      <Name>ADDRESSID</Name>
+      <ElementPath>ADDRESSID</ElementPath>
+      <Type>Integer</Type>
+    </PropertyDefn>
+    <PropertyDefn>
+      <Name>BASEID</Name>
+      <ElementPath>BASEID</ElementPath>
+      <Type>Integer</Type>
+    </PropertyDefn>
+    <PropertyDefn>
+      <Name>REVDATE</Name>
+      <ElementPath>REVDATE</ElementPath>
+      <Type>String</Type>
+      <Width>10</Width>
+    </PropertyDefn>
+    <PropertyDefn>
+      <Name>FLOOR</Name>
+      <ElementPath>FLOOR</ElementPath>
+      <Type>Integer</Type>
+    </PropertyDefn>
+    <PropertyDefn>
+      <Name>NUMBER</Name>
+      <ElementPath>NUMBER</ElementPath>
+      <Type>Integer</Type>
+    </PropertyDefn>
+    <PropertyDefn>
+      <Name>ZIP</Name>
+      <ElementPath>ZIP</ElementPath>
+      <Type>Integer</Type>
+    </PropertyDefn>
+    <PropertyDefn>
+      <Name>ACTIVE</Name>
+      <ElementPath>ACTIVE</ElementPath>
+      <Type>String</Type>
+      <Width>3</Width>
+    </PropertyDefn>
+    <PropertyDefn>
+      <Name>MAILING</Name>
+      <ElementPath>MAILING</ElementPath>
+      <Type>String</Type>
+      <Width>3</Width>
+    </PropertyDefn>
+    <PropertyDefn>
+      <Name>FENAME</Name>
+      <ElementPath>FENAME</ElementPath>
+      <Type>String</Type>
+      <Width>14</Width>
+    </PropertyDefn>
+    <PropertyDefn>
+      <Name>FNAME</Name>
+      <ElementPath>FNAME</ElementPath>
+      <Type>String</Type>
+      <Width>14</Width>
+    </PropertyDefn>
+    <PropertyDefn>
+      <Name>FTYPE</Name>
+      <ElementPath>FTYPE</ElementPath>
+      <Type>String</Type>
+      <Width>2</Width>
+    </PropertyDefn>
+    <PropertyDefn>
+      <Name>STRNAME</Name>
+      <ElementPath>STRNAME</ElementPath>
+      <Type>String</Type>
+      <Width>17</Width>
+    </PropertyDefn>
+    <PropertyDefn>
+      <Name>id</Name>
+      <ElementPath>id</ElementPath>
+      <Type>String</Type>
+      <Width>9</Width>
+    </PropertyDefn>
+  </GMLFeatureClass>
+</GMLFeatureClassList>
diff --git a/openaddr/tests/conforms/lake-man-gpkg.json b/openaddr/tests/conforms/lake-man-gpkg.json
new file mode 100644
index 00000000..0c6b91e0
--- /dev/null
+++ b/openaddr/tests/conforms/lake-man-gpkg.json
@@ -0,0 +1,18 @@
+{
+    "schema": 2,
+    "layers": {
+        "addresses": [{
+            "name": "default",
+            "data": "http://fake-web/lake-man.gpkg",
+            "cache": "http://fake-cache/lake-man.gpkg",
+            "protocol": "http",
+            "conform": {
+                "lon": "X",
+                "lat": "Y",
+                "number": "NUMBER",
+                "street": "STRNAME",
+                "format": "gpkg"
+            }
+        }]
+    }
+}
diff --git a/openaddr/tests/conforms/lake-man.gpkg b/openaddr/tests/conforms/lake-man.gpkg
new file mode 100644
index 00000000..0a3d22eb
Binary files /dev/null and b/openaddr/tests/conforms/lake-man.gpkg differ