diff --git a/dask_ml/_partial.py b/dask_ml/_partial.py
index 0bff82b53..0495edf9e 100644
--- a/dask_ml/_partial.py
+++ b/dask_ml/_partial.py
@@ -7,6 +7,7 @@
 import numpy as np
 import sklearn.utils
 from dask.delayed import Delayed
+from dask.highlevelgraph import HighLevelGraph
 from toolz import partial
 
 logger = logging.getLogger(__name__)
@@ -120,19 +121,10 @@ def fit(
         }
     )
 
-    graphs = {x_name: x.__dask_graph__(), name: dsk}
-    if hasattr(y, "__dask_graph__"):
-        graphs[y_name] = y.__dask_graph__()
-
-    try:
-        from dask.highlevelgraph import HighLevelGraph
-
-        new_dsk = HighLevelGraph.merge(*graphs.values())
-    except ImportError:
-        from dask import sharedict
-
-        new_dsk = sharedict.merge(*graphs.values())
-
+    dependencies = [x]
+    if y is not None:
+        dependencies.append(y)
+    new_dsk = HighLevelGraph.from_collections(name, dsk, dependencies=dependencies)
     value = Delayed((name, nblocks - 1), new_dsk)
 
     if compute: