diff --git a/packages/cli/src/__tests__/active-workflow-manager.test.ts b/packages/cli/src/__tests__/active-workflow-manager.test.ts
index 55775f64b1..f501a636db 100644
--- a/packages/cli/src/__tests__/active-workflow-manager.test.ts
+++ b/packages/cli/src/__tests__/active-workflow-manager.test.ts
@@ -148,4 +148,21 @@ describe('ActiveWorkflowManager', () => {
 			);
 		});
 	});
+
+	describe('addActiveWorkflows', () => {
+		test('should prevent concurrent activations', async () => {
+			const getAllActiveIds = jest.spyOn(workflowRepository, 'getAllActiveIds');
+
+			workflowRepository.getAllActiveIds.mockImplementation(
+				async () => await new Promise((resolve) => setTimeout(() => resolve(['workflow-1']), 50)),
+			);
+
+			await Promise.all([
+				activeWorkflowManager.addActiveWorkflows('init'),
+				activeWorkflowManager.addActiveWorkflows('leadershipChange'),
+			]);
+
+			expect(getAllActiveIds).toHaveBeenCalledTimes(1);
+		});
+	});
 });
diff --git a/packages/cli/src/active-workflow-manager.ts b/packages/cli/src/active-workflow-manager.ts
index 6ce6903a83..009116061e 100644
--- a/packages/cli/src/active-workflow-manager.ts
+++ b/packages/cli/src/active-workflow-manager.ts
@@ -418,30 +418,42 @@ export class ActiveWorkflowManager {
 		executeErrorWorkflow(workflowData, fullRunData, mode);
 	}
 
+	private isActivationInProgress = false;
+
 	/**
 	 * Register as active in memory all workflows stored as `active`,
 	 * only on instance init or (in multi-main setup) on leadership change.
 	 */
 	async addActiveWorkflows(activationMode: 'init' | 'leadershipChange') {
-		const dbWorkflowIds = await this.workflowRepository.getAllActiveIds();
-
-		if (dbWorkflowIds.length === 0) return;
-
-		if (this.instanceSettings.isLeader) {
-			this.logger.info('Start Active Workflows:');
+		if (this.isActivationInProgress) {
+			this.logger.debug(`Skipping activation - already in progress for mode: ${activationMode}`);
+			return;
 		}
 
-		const batches = chunk(dbWorkflowIds, this.workflowsConfig.activationBatchSize);
+		this.isActivationInProgress = true;
+		try {
+			const dbWorkflowIds = await this.workflowRepository.getAllActiveIds();
 
-		for (const batch of batches) {
-			const activationPromises = batch.map(async (dbWorkflowId) => {
-				await this.activateWorkflow(dbWorkflowId, activationMode);
-			});
+			if (dbWorkflowIds.length === 0) return;
 
-			await Promise.all(activationPromises);
+			if (this.instanceSettings.isLeader) {
+				this.logger.info('Start Active Workflows:');
+			}
+
+			const batches = chunk(dbWorkflowIds, this.workflowsConfig.activationBatchSize);
+
+			for (const batch of batches) {
+				const activationPromises = batch.map(async (dbWorkflowId) => {
+					await this.activateWorkflow(dbWorkflowId, activationMode);
+				});
+
+				await Promise.all(activationPromises);
+			}
+
+			this.logger.debug('Finished activating all workflows');
+		} finally {
+			this.isActivationInProgress = false;
 		}
-
-		this.logger.debug('Finished activating all workflows');
 	}
 
 	private async activateWorkflow(