diff --git a/docs/changelog/7.x.x.txt b/docs/changelog/7.x.x.txt
index 68aed4767..1e2cbd114 100644
--- a/docs/changelog/7.x.x.txt
+++ b/docs/changelog/7.x.x.txt
@@ -11,6 +11,7 @@
  - Set a minimum package weight of 0.1 oz for the USPS driver.
  - Handle per package errors in USPS response data.
  - fixed #11207: Shop Email receipts going out to everyone.
+ - fixed tag-caching bug in Survey ExpressionEngine
 
 7.8.3
  - Rewrote Spectre's workflow queues to prevent it from "forgetting" about some workflows.
diff --git a/lib/WebGUI/Asset/Wobject/Survey/ExpressionEngine.pm b/lib/WebGUI/Asset/Wobject/Survey/ExpressionEngine.pm
index 17abd5ed5..3afa244d0 100644
--- a/lib/WebGUI/Asset/Wobject/Survey/ExpressionEngine.pm
+++ b/lib/WebGUI/Asset/Wobject/Survey/ExpressionEngine.pm
@@ -24,8 +24,10 @@ use WebGUI::Asset;
 use WebGUI::Asset::Wobject::Survey;
 Params::Validate::validation_options( on_fail => sub { WebGUI::Error::InvalidParam->throw( error => shift ) } );
 
-# We need these as semi-globals so that utility subs (which are shared with the safe compartment)
+# We need these as file-scoped lexicals so that our utility subs (which are shared with the safe compartment)
 # can access them.
+# N.B. If you add any new ones, make sure you initialize them in L<run> otherwise they will be cached across
+# unrelated engine runs, which leads to bugs that are hairy to track down
 my $session;
 my $values;
 my $scores;
@@ -431,7 +433,7 @@ sub run {
     my ( $s, $expression, $opts )
         = validate_pos( @_, { isa => 'WebGUI::Session' }, { type => SCALAR }, { type => HASHREF, default => {} } );
 
-    # Init package globals
+    # Initialize all file-scoped lexicals that our Safe utility subs have access to
     $session = $s;
     $values = $opts->{values} || {};
     $scores = $opts->{scores} || {};
@@ -439,6 +441,7 @@ sub run {
     $validate = $opts->{validate};
     $validTargets = $opts->{validTargets};
     $tags = $opts->{tags} || {};
+    $otherInstances = {};
 
     if ( !$session->config->get('enableSurveyExpressionEngine') ) {
         $session->log->debug('enableSurveyExpressionEngine config option disabled, skipping');
diff --git a/t/Asset/Wobject/Survey/ExpressionEngine.t b/t/Asset/Wobject/Survey/ExpressionEngine.t
index 89ffc2eaa..8acc0db17 100644
--- a/t/Asset/Wobject/Survey/ExpressionEngine.t
+++ b/t/Asset/Wobject/Survey/ExpressionEngine.t
@@ -22,7 +22,7 @@ my $session = WebGUI::Test->session;
 
 #----------------------------------------------------------------------------
 # Tests
-my $tests = 58;
+my $tests = 60;
 plan tests => $tests + 1;
 
 #----------------------------------------------------------------------------
@@ -236,8 +236,34 @@ SKIP: {
         { jump => 'target', tags => {} }, 'external score resolves ok too' );
     cmp_deeply( $e->run( $session, qq{jump {scoreX('$url', ext_s0) == 200} target}, {userId => $user->userId} ),
         { jump => 'target', tags => {} }, 'external score section totals work too' );
-    cmp_deeply( $e->run( $session, qq{jump {taggedX('$url', ext_tag, 1) == 199} target}, {userId => $user->userId} ),
+    cmp_deeply( $e->run( $session, qq{jump {taggedX('$url', ext_tag) == 199} target}, {userId => $user->userId} ),
         { jump => 'target', tags => {} }, 'external tag lookups work too' );
+    
+    # Test for nasty bugs caused by file-scoped lexicals not being properly initialised in L<ExpressionEngine::run>
+    {
+        # Create a second test user
+        my $survey2 = WebGUI::Asset::Wobject::Survey->new($session, $survey->getId);
+        my $user2 = WebGUI::User->new( $session, 'new' );
+        WebGUI::Test->usersToDelete($user2);
+        $session->user({userId => $user2->userId});
+        my $responseId2 = $survey2->responseId( { userId => $user2->userId } );
+        my $rJSON2 = $survey2->responseJSON(undef, $responseId2);
+        $rJSON2->recordResponses({
+            '0-0-0'        => 'My ext_s0q0a0 answer',
+            '0-1-0'        => 'My ext_s0q1a0 answer',
+        });
+        $rJSON2->processExpression(q{ tag(ext_tag, 299) });
+        # Remember to persist our changes..
+        $survey2->persistSurveyJSON();
+        $survey2->persistResponseJSON();
+        $survey2->surveyEnd;
+        
+        cmp_deeply( $e->run( $session, qq{jump {taggedX('$url', ext_tag) == 299} target}, {userId => $user2->userId} ),
+            { jump => 'target', tags => {} }, 'external tag not cached' );
+        
+        cmp_deeply( $e->run( $session, qq{jump {taggedX('$url', ext_tag) == 199} target}, {userId => $user->userId} ),
+            { jump => 'target', tags => {} }, 'first external tag lookups still works' );
+    }
 }
 
 #----------------------------------------------------------------------------