diff --git a/classes/migration/upgrade/v3_4_0/I12140_MissingDecisionConstantsUpdate.php b/classes/migration/upgrade/v3_4_0/I12140_MissingDecisionConstantsUpdate.php
new file mode 100644
index 0000000000..75e96d0a3c
--- /dev/null
+++ b/classes/migration/upgrade/v3_4_0/I12140_MissingDecisionConstantsUpdate.php
@@ -0,0 +1,81 @@
+<?php
+
+/**
+ * @file classes/migration/upgrade/v3_4_0/I12140_MissingDecisionConstantsUpdate.php
+ *
+ * Copyright (c) 2025 Simon Fraser University
+ * Copyright (c) 2025 John Willinsky
+ * Distributed under the GNU GPL v3. For full terms see the file docs/COPYING.
+ *
+ * @class I12140_MissingDecisionConstantsUpdate
+ *
+ * @brief Fixed the missing decisions data in stages
+ *
+ * @see https://github.com/pkp/pkp-lib/issues/12140
+ */
+
+namespace APP\migration\upgrade\v3_4_0;
+
+use APP\core\Application;
+use Illuminate\Support\Facades\DB;
+use PKP\install\DowngradeNotSupportedException;
+
+class I12140_MissingDecisionConstantsUpdate extends \PKP\migration\upgrade\v3_4_0\I7725_DecisionConstantsUpdate
+{
+    /**
+     * Get the decisions constants mappings
+     */
+    public function getDecisionMappings(): array
+    {
+        return [
+            // \PKP\decision\Decision::INITIAL_DECLINE
+            [
+                'stage_id' => [WORKFLOW_STAGE_ID_PRODUCTION],
+                'current_value' => 9,
+                'updated_value' => 8,
+            ],
+            // \PKP\decision\Decision::REVERT_INITIAL_DECLINE
+            // Was REVERT_DECLINE (17) in OPS 3.3, maps to REVERT_INITIAL_DECLINE (16) in 3.4
+            [
+                'stage_id' => [WORKFLOW_STAGE_ID_PRODUCTION],
+                'current_value' => 17,
+                'updated_value' => 16,
+            ],
+        ];
+    }
+
+    /**
+     * Run the migrations.
+     */
+    public function up(): void
+    {
+        // If the first installed version is 3.4.0+
+        // no legacy data exists, nothing to do
+        $firstInstalledVersion = DB::table('versions')
+            ->where('product', Application::get()->getName())
+            ->where('product_type', 'core')
+            ->orderBy('date_installed')
+            ->first();
+
+        if ($firstInstalledVersion->major == 3 && $firstInstalledVersion->minor == 4) {
+            return;
+        }
+
+        // Date-based filtering is not needed here (unlike OJS/OMP I12140).
+        // In OJS/OMP, I7725 ran during the original 3.3→3.4 upgrade but had bugs,
+        // so date filtering distinguishes "migrated correctly" vs "migrated incorrectly" rows.
+        // For OPS, I7725 was entirely missing — it never ran at all for these installations.
+        // So ALL rows with old values (9, 17) need migrating.
+        // These old values are distinct from the new 3.4 values (8, 16),
+        // so parent::up() only matches unmigrated legacy rows — no date filter required.
+        parent::up();
+    }
+
+    /**
+     * Reverse the migrations.
+     */
+    public function down(): void
+    {
+        throw new DowngradeNotSupportedException();
+    }
+}
diff --git a/classes/migration/upgrade/v3_4_0/I7725_DecisionConstantsUpdate.php b/classes/migration/upgrade/v3_4_0/I7725_DecisionConstantsUpdate.php
new file mode 100644
index 0000000000..3e39cede25
--- /dev/null
+++ b/classes/migration/upgrade/v3_4_0/I7725_DecisionConstantsUpdate.php
@@ -0,0 +1,36 @@
+<?php
+
+/**
+ * @file classes/migration/upgrade/v3_4_0/I7725_DecisionConstantsUpdate.php
+ *
+ * Copyright (c) 2014-2022 Simon Fraser University
+ * Copyright (c) 2000-2022 John Willinsky
+ * Distributed under the GNU GPL v3. For full terms see the file docs/COPYING.
+ *
+ * @class I7725_DecisionConstantsUpdate
+ *
+ * @brief Editorial decision constant sync up across all application
+ *
+ * @see https://github.com/pkp/pkp-lib/issues/7725
+ */
+
+namespace APP\migration\upgrade\v3_4_0;
+
+class I7725_DecisionConstantsUpdate extends \PKP\migration\upgrade\v3_4_0\I7725_DecisionConstantsUpdate
+{
+    /**
+     * Get the decisions constants mappings
+     *
+     * OPS only has 2 decisions at PRODUCTION stage: INITIAL_DECLINE and REVERT_DECLINE.
+     * No stage_id filtering needed: only 2 unique values with no collision risk,
+     * and the parent class's updated_at tracking prevents any issues.
+     * See https://github.com/pkp/pkp-lib/issues/12357
+     */
+    public function getDecisionMappings(): array
+    {
+        return [
+            ['current_value' => 9,  'updated_value' => 8],   // INITIAL_DECLINE
+            ['current_value' => 17, 'updated_value' => 16],  // REVERT_INITIAL_DECLINE (was REVERT_DECLINE in 3.3)
+        ];
+    }
+}
diff --git a/dbscripts/xml/upgrade.xml b/dbscripts/xml/upgrade.xml
index da5aabd976..3b99de6f94 100644
--- a/dbscripts/xml/upgrade.xml
+++ b/dbscripts/xml/upgrade.xml
@@ -50,6 +50,7 @@
 		<migration class="APP\migration\upgrade\v3_4_0\I7264_UpdateEmailTemplates"/>
 		<migration class="APP\migration\upgrade\v3_4_0\I7014_DoiMigration"/>
 		<migration class="APP\migration\upgrade\v3_4_0\I7265_EditorialDecisions"/>
+		<migration class="APP\migration\upgrade\v3_4_0\I7725_DecisionConstantsUpdate"/>
 		<migration class="APP\migration\upgrade\v3_4_0\I5774_SetRelationVariables"/>
 		<migration class="PKP\migration\upgrade\v3_4_0\I7624_StrftimeDeprecation"/>
 		<migration class="PKP\migration\upgrade\v3_4_0\I7592_RemoveUnusedEmailTemplates"/>
@@ -125,6 +126,11 @@
 		<migration class="PKP\migration\upgrade\v3_4_0\I9822_ChangeUsageStatsTemporaryTablesIndexes"/>
 	</upgrade>
 
+	<upgrade minversion="3.4.0.0" maxversion="3.4.0.10">
+		<!-- Only existing 3.4 installations upgraded from pre-3.4 that need it -->
+		<migration class="APP\migration\upgrade\v3_4_0\I12140_MissingDecisionConstantsUpdate"/>
+	</upgrade>
+
 	<!-- update plugin configuration - should be done as the final upgrade task -->
 	<code function="addPluginVersions" />
 </install>