diff --git a/amber/src/main/scala/org/apache/texera/web/resource/dashboard/user/workflow/WorkflowResource.scala b/amber/src/main/scala/org/apache/texera/web/resource/dashboard/user/workflow/WorkflowResource.scala
index 315418516d3..43eb4bb5c55 100644
--- a/amber/src/main/scala/org/apache/texera/web/resource/dashboard/user/workflow/WorkflowResource.scala
+++ b/amber/src/main/scala/org/apache/texera/web/resource/dashboard/user/workflow/WorkflowResource.scala
@@ -840,6 +840,9 @@ class WorkflowResource extends LazyLogging {
       .where(WORKFLOW.WID.eq(wid))
       .and(WORKFLOW.IS_PUBLIC.isTrue)
       .fetchOne()
+    if (workflow == null) {
+      throw new NotFoundException(s"Public workflow with id $wid not found")
+    }
     WorkflowWithPrivilege(
       workflow.getName,
       workflow.getDescription,
diff --git a/amber/src/test/scala/org/apache/texera/web/resource/dashboard/file/WorkflowResourceSpec.scala b/amber/src/test/scala/org/apache/texera/web/resource/dashboard/file/WorkflowResourceSpec.scala
index c2852fc6548..9d7883f102e 100644
--- a/amber/src/test/scala/org/apache/texera/web/resource/dashboard/file/WorkflowResourceSpec.scala
+++ b/amber/src/test/scala/org/apache/texera/web/resource/dashboard/file/WorkflowResourceSpec.scala
@@ -1027,6 +1027,12 @@ class WorkflowResourceSpec
     assertThrows[ForbiddenException](workflowResource.makePublic(wid, sessionUser2))
   }
 
+  "WorkflowResource.retrievePublicWorkflow" should "hide private and missing workflows" in {
+    val wid = seedWorkflow(sessionUser1, "private-wf").workflow.getWid
+    assertThrows[NotFoundException](workflowResource.retrievePublicWorkflow(wid))
+    assertThrows[NotFoundException](workflowResource.retrievePublicWorkflow(wid + 100000))
+  }
+
   "WorkflowResource.searchWorkflowByOperator" should "return only workflows whose content contains the operator" in {
     val wid = seedWorkflow(
       sessionUser1,