diff --git a/docs/changelog/7.x.x.txt b/docs/changelog/7.x.x.txt
index 11566be53..5f97e5d2e 100644
--- a/docs/changelog/7.x.x.txt
+++ b/docs/changelog/7.x.x.txt
@@ -20,6 +20,7 @@
  - fixed #12001: Shelf product import mangles price
  - fixed #11945: Slow SQL access for duplicate e-mail address lookups
  - fixed #11960: Billing address mandatory fields not specified
+ - fixed #11975: Cannot paste threads: "Cannot call method isa()"
 
 7.10.6
  - fixed #11974: Toolbar icons unclickable in Webkit using HTML5
diff --git a/lib/WebGUI/AssetClipboard.pm b/lib/WebGUI/AssetClipboard.pm
index f81565959..9289979f0 100644
--- a/lib/WebGUI/AssetClipboard.pm
+++ b/lib/WebGUI/AssetClipboard.pm
@@ -317,6 +317,7 @@ sub pasteInFork {
     my ( $process, $args ) = @_;
     my $session = $process->session;
     my $self    = WebGUI::Asset->new( $session, $args->{assetId} );
+    $session->asset( $self );
     my @roots   = grep { $_ && $_->canEdit }
         map { WebGUI::Asset->newPending( $session, $_ ) } @{ $args->{list} };
 
diff --git a/t/Asset/AssetClipboard.t b/t/Asset/AssetClipboard.t
index 526425e50..acf95a1e0 100644
--- a/t/Asset/AssetClipboard.t
+++ b/t/Asset/AssetClipboard.t
@@ -21,9 +21,11 @@ use WebGUI::Utility;
 use WebGUI::Asset;
 use WebGUI::VersionTag;
 use Test::MockObject;
+use Test::MockObject::Extends;
+use WebGUI::Fork;
 
 use Test::More; # increment this value for each test you create
-plan tests => 29;
+plan tests => 30;
 
 my $session = WebGUI::Test->session;
 $session->user({userId => 3});
@@ -200,3 +202,34 @@ $shortcut->publish;
 $page->cut;
 
 is $shortcut->paste($page->getId), 0, 'cannot paste below shortcuts';
+
+####################################################
+#
+# pasteInFork
+#
+####################################################
+
+$session->user({ userId => "3" });
+my $process = Test::MockObject::Extends->new( 'WebGUI::Fork' );
+$process->mock( "update" => sub { } ); # do nothing on update. we don't care
+$process->mock( "session" => sub { return $session } );
+
+# Try with a Collaboration and some Threads
+my $tag = WebGUI::VersionTag->getWorking( $session );
+my $collab = $tempspace->addChild({
+    className => 'WebGUI::Asset::Wobject::Collaboration',
+    groupIdEdit => "3",
+    status => "pending",
+    tagId => $tag->getId,
+});
+my $thread = $collab->addChild({
+    className => 'WebGUI::Asset::Post::Thread',
+    groupIdEdit => "3",
+    status => "pending",
+    tagId => $tag->getId,
+}, undef, undef, { skipAutoCommitWorkflows => 1 });
+$tag->commit;
+$thread->cut;
+WebGUI::Asset::pasteInFork( $process, { assetId => $collab->getId, list => [ $thread->getId ] } );
+$thread = $thread->cloneFromDb;
+is( $thread->get('state'), 'published', 'thread is pasted' );