diff --git a/sources/multi/setup.py b/sources/multi/setup.py
index 642ab4e35..9ce58718e 100644
--- a/sources/multi/setup.py
+++ b/sources/multi/setup.py
@@ -45,6 +45,7 @@ def prerelease_local_scheme(version):
     install_requires=[
         'jsonschema',
         'large-image>=1.0.0',
+        'pyyaml',
         'scipy',
     ],
     extras_require={
diff --git a/test/datastore.py b/test/datastore.py
index 0eb10049e..64ee7c797 100644
--- a/test/datastore.py
+++ b/test/datastore.py
@@ -72,6 +72,9 @@
     # Geospatial file without a projection
     # Source: generated from geojs oahu sample and a script
     'oahu-dense.tiff': 'sha512:414b7807f14991d6f8229134ad6ccbc2cc2d4b05423ccebfd3ede7d7323dfcf04ef1a7b2c2b4c45c31f8a36bccd390782af3e7d3e99f01f1b95650c5da1f122b',  # noqa
+    # Multi source file using different sources
+    # Source: manually generated.
+    'multi_source.yml': 'sha512:81d7768b06eca6903082daa5b91706beaac8557ba4cede7f826524303df69a33478d6bb205c56af7ee2b45cd7d75897cc4b5704f743ddbf71bb3537ed3b9e8a8',  # noqa
 }
 
 
diff --git a/test/test_files/multi3.yml b/test/test_files/multi3.yml
new file mode 100644
index 000000000..d56f27321
--- /dev/null
+++ b/test/test_files/multi3.yml
@@ -0,0 +1,9 @@
+---
+name: Multi orientation
+description: A test multi file
+scale:
+  mm_x: 0.0005
+  mm_y: 0.0005
+sources:
+  - path: .
+    pathPattern: 'test_orient(?P<z1>[1-8])\.tif'
diff --git a/test/test_files/multi_composite.yml b/test/test_files/multi_composite.yml
new file mode 100644
index 000000000..ab9740466
--- /dev/null
+++ b/test/test_files/multi_composite.yml
@@ -0,0 +1,50 @@
+---
+name: Multi orientation
+description: A test multi file
+scale:
+  mm_x: 0.0005
+  mm_y: 0.0005
+width: 360
+height: 360
+sources:
+  - name: First image
+    path: ./test_orient1.tif
+    z: 0
+    position:
+      x: 0
+      y: 0
+  - path: ./test_orient2.tif
+    z: 0
+    position:
+      x: 180
+      y: 0
+  - path: ./test_orient3.tif
+    z: 0
+    position:
+      x: 0
+      y: 180
+  - path: ./test_orient4.tif
+    z: 0
+    position:
+      x: 180
+      y: 180
+  - path: ./test_orient5.tif
+    z: 1
+    position:
+      x: 0
+      y: 0
+  - path: ./test_orient6.tif
+    z: 1
+    position:
+      x: 180
+      y: 0
+  - path: ./test_orient7.tif
+    z: 1
+    position:
+      x: 0
+      y: 180
+  - path: ./test_orient8.tif
+    z: 1
+    position:
+      x: 180
+      y: 180
diff --git a/test/test_files/multi_simple_scaling.yml b/test/test_files/multi_simple_scaling.yml
new file mode 100644
index 000000000..22f22310e
--- /dev/null
+++ b/test/test_files/multi_simple_scaling.yml
@@ -0,0 +1,39 @@
+---
+name: Multi orientation
+description: A test multi file
+scale:
+  mm_x: 0.0005
+  mm_y: 0.0005
+width: 2048
+height: 1540
+tileWidth: 256
+tileHeight: 256
+backgroundColor:
+  - 0
+  - 0
+  - 255
+sources:
+  - path: ./test_orient1.tif
+    z: 0
+  - path: ./test_orient2.tif
+    z: 1
+    position:
+      scale: 4
+  - path: ./test_orient3.tif
+    z: 2
+    position:
+      scale: 0.25
+  - path: ./test_orient4.tif
+    z: 3
+    position:
+      x: 137
+      y: 32
+      scale: 4
+  - path: ./test_orient5.tif
+    z: 4
+  - path: ./test_orient6.tif
+    z: 5
+  - path: ./test_orient7.tif
+    z: 6
+  - path: ./test_orient8.tif
+    z: 7
diff --git a/test/test_source_base.py b/test/test_source_base.py
index 98bc80c81..831601a32 100644
--- a/test/test_source_base.py
+++ b/test/test_source_base.py
@@ -30,6 +30,9 @@
         'noread': r'(huron\.image2_jpeg2k|sample_jp2k_33003|TCGA-DU-6399|\.(ome.tiff)$)',
         # we should only test this with a projection
         'skipTiles': r''},
+    'multi': {
+        'read': r'\.(yml|yaml)$',
+    },
     'nd2': {'read': r'\.(nd2)$'},
     'ometiff': {'read': r'\.(ome\.tif.*)$'},
     'openjpeg': {'read': r'\.(jp2)$'},
diff --git a/test/test_source_multi.py b/test/test_source_multi.py
new file mode 100644
index 000000000..52a8dab17
--- /dev/null
+++ b/test/test_source_multi.py
@@ -0,0 +1,88 @@
+import os
+
+import large_image_source_multi
+import pytest
+
+from . import utilities
+from .datastore import datastore
+
+
+@pytest.mark.parametrize('filename', [
+    'multi1.yml',
+    'multi2.yml',
+    'multi3.yml',
+])
+def testTilesFromMulti(filename):
+    testDir = os.path.dirname(os.path.realpath(__file__))
+    imagePath = os.path.join(testDir, 'test_files', filename)
+    source = large_image_source_multi.open(imagePath)
+    tileMetadata = source.getMetadata()
+    assert tileMetadata['tileWidth'] == 64
+    assert tileMetadata['tileHeight'] == 64
+    assert tileMetadata['sizeX'] == 180
+    assert tileMetadata['sizeY'] == 180
+    assert tileMetadata['levels'] == 3
+    assert len(tileMetadata['frames']) == 8
+
+    utilities.checkTilesZXY(source, tileMetadata)
+
+
+def testTilesFromMultiComposite():
+    testDir = os.path.dirname(os.path.realpath(__file__))
+    imagePath = os.path.join(testDir, 'test_files', 'multi_composite.yml')
+    source = large_image_source_multi.open(imagePath)
+    tileMetadata = source.getMetadata()
+    assert tileMetadata['tileWidth'] == 64
+    assert tileMetadata['tileHeight'] == 64
+    assert tileMetadata['sizeX'] == 360
+    assert tileMetadata['sizeY'] == 360
+    assert tileMetadata['levels'] == 4
+    assert len(tileMetadata['frames']) == 2
+
+    utilities.checkTilesZXY(source, tileMetadata)
+
+
+def testTilesFromMultiSimpleScaling():
+    testDir = os.path.dirname(os.path.realpath(__file__))
+    imagePath = os.path.join(testDir, 'test_files', 'multi_simple_scaling.yml')
+    source = large_image_source_multi.open(imagePath)
+    tileMetadata = source.getMetadata()
+    assert tileMetadata['tileWidth'] == 256
+    assert tileMetadata['tileHeight'] == 256
+    assert tileMetadata['sizeX'] == 2048
+    assert tileMetadata['sizeY'] == 1540
+    assert tileMetadata['levels'] == 4
+    assert len(tileMetadata['frames']) == 8
+
+    for frame in range(len(tileMetadata['frames'])):
+        utilities.checkTilesZXY(source, tileMetadata, tileParams={'frame': frame})
+
+
+def testTilesFromMultiMultiSource():
+    imagePath = datastore.fetch('multi_source.yml')
+    source = large_image_source_multi.open(imagePath)
+    tileMetadata = source.getMetadata()
+    assert tileMetadata['tileWidth'] == 256
+    assert tileMetadata['tileHeight'] == 256
+    assert tileMetadata['sizeX'] == 55988
+    assert tileMetadata['sizeY'] == 16256
+    assert tileMetadata['levels'] == 9
+    assert len(tileMetadata['frames']) == 300
+
+    utilities.checkTilesZXY(source, tileMetadata)
+    utilities.checkTilesZXY(source, tileMetadata, tileParams={'frame': 50})
+
+
+def testInternalMetadata():
+    imagePath = datastore.fetch('multi_source.yml')
+    source = large_image_source_multi.open(imagePath)
+    metadata = source.getInternalMetadata()
+    assert 'frames' in metadata
+
+
+def testAssociatedImages():
+    imagePath = datastore.fetch('multi_source.yml')
+    source = large_image_source_multi.open(imagePath)
+    assert 'label' in source.getAssociatedImagesList()
+    image, mimeType = source.getAssociatedImage('label')
+    assert image[:len(utilities.JPEGHeader)] == utilities.JPEGHeader