diff --git a/patch.go b/patch.go
index e736759..f185a45 100644
--- a/patch.go
+++ b/patch.go
@@ -392,17 +392,13 @@ func (d *partialDoc) add(key string, val *lazyNode) error {
 }
 
 func (d *partialDoc) get(key string) (*lazyNode, error) {
-	v, ok := (*d)[key]
-	if !ok {
-		return v, errors.Wrapf(ErrMissing, "unable to get nonexistent key: %s", key)
-	}
-	return v, nil
+	return (*d)[key], nil
 }
 
 func (d *partialDoc) remove(key string) error {
 	_, ok := (*d)[key]
 	if !ok {
-		return errors.Wrapf(ErrMissing, "unable to remove nonexistent key: %s", key)
+		return errors.Wrapf(ErrMissing, "Unable to remove nonexistent key: %s", key)
 	}
 
 	delete(*d, key)
@@ -624,7 +620,7 @@ func (p Patch) test(doc *container, op Operation) error {
 	}
 
 	val, err := con.get(key)
-	if err != nil && errors.Cause(err) != ErrMissing {
+	if err != nil {
 		return errors.Wrapf(err, "error in test for path: '%s'", path)
 	}
 
diff --git a/patch_test.go b/patch_test.go
index 5cd519d..40c9b26 100644
--- a/patch_test.go
+++ b/patch_test.go
@@ -186,11 +186,6 @@ var Cases = []Case{
 		`[{"op": "copy", "path": "/foo/0", "from": "/foo"}]`,
 		`{ "foo": [["bar"], "bar"]}`,
 	},
-	{
-		`{ "foo": null}`,
-		`[{"op": "copy", "path": "/bar", "from": "/foo"}]`,
-		`{ "foo": null, "bar": null}`,
-	},
 	{
 		`{ "foo": ["bar","qux","baz"]}`,
 		`[ { "op": "remove", "path": "/foo/-2"}]`,
@@ -337,15 +332,6 @@ var BadCases = []BadCase{
 		`{ "foo": [ "all", "grass", "cows", "eat" ] }`,
 		`[ { "op": "move", "from": "/foo/1", "path": "/foo/4" } ]`,
 	},
-	{
-		`{ "baz": "qux" }`,
-		`[ { "op": "replace", "path": "/foo", "value": "bar" } ]`,
-	},
-	// Can't copy from non-existent "from" key.
-	{
-		`{ "foo": "bar"}`,
-		`[{"op": "copy", "path": "/qux", "from": "/baz"}]`,
-	},
 }
 
 // This is not thread safe, so we cannot run patch tests in parallel.
@@ -473,18 +459,6 @@ var TestCases = []TestCase{
 		false,
 		"/foo",
 	},
-	{
-		`{ "foo": "bar" }`,
-		`[ { "op": "test", "path": "/baz", "value": "bar" } ]`,
-		false,
-		"/baz",
-	},
-	{
-		`{ "foo": "bar" }`,
-		`[ { "op": "test", "path": "/baz", "value": null } ]`,
-		true,
-		"/baz",
-	},
 }
 
 func TestAllTest(t *testing.T) {