diff --git a/schemas/spec-driven/schema.yaml b/schemas/spec-driven/schema.yaml
index 45f61e222..ebf17b41e 100644
--- a/schemas/spec-driven/schema.yaml
+++ b/schemas/spec-driven/schema.yaml
@@ -146,7 +146,7 @@ artifacts:
       - design
 
 apply:
-  requires: [tasks]
+  requires: [specs, tasks]
   tracks: tasks.md
   instruction: |
     Read context files, work through pending tasks, mark complete as you go.
diff --git a/src/commands/workflow/instructions.ts b/src/commands/workflow/instructions.ts
index 10a5fac16..a28b3e32b 100644
--- a/src/commands/workflow/instructions.ts
+++ b/src/commands/workflow/instructions.ts
@@ -395,7 +395,11 @@ export async function generateApplyInstructions(
 
   if (missingArtifacts.length > 0) {
     state = 'blocked';
-    instruction = `Cannot apply this change yet. Missing artifacts: ${missingArtifacts.join(', ')}.\nUse the openspec-continue-change skill to create the missing artifacts first.`;
+    const specsHint =
+      missingArtifacts.includes('specs') && context.schemaName === 'spec-driven'
+        ? '\nDelta specs must exist under changes/<name>/specs/ before implementation.'
+        : '';
+    instruction = `Cannot apply this change yet. Missing artifacts: ${missingArtifacts.join(', ')}.${specsHint}\nUse the openspec-continue-change skill to create the missing artifacts first.`;
   } else if (tracksFile && !tracksFileExists) {
     // Tracking file configured but doesn't exist yet
     const tracksFilename = path.basename(tracksFile);
@@ -467,10 +471,13 @@ export async function applyInstructionsCommand(options: ApplyInstructionsOptions
 
     if (options.json) {
       console.log(JSON.stringify({ ...instructions, root: toRootOutput(root) }, null, 2));
-      return;
+    } else {
+      printApplyInstructionsText(instructions);
     }
 
-    printApplyInstructionsText(instructions);
+    if (instructions.state === 'blocked') {
+      process.exitCode = 1;
+    }
   } catch (error) {
     spinner?.stop();
     throw error;
diff --git a/test/commands/artifact-workflow.test.ts b/test/commands/artifact-workflow.test.ts
index a286422a8..01ddce3d6 100644
--- a/test/commands/artifact-workflow.test.ts
+++ b/test/commands/artifact-workflow.test.ts
@@ -434,15 +434,30 @@ describe('artifact-workflow CLI commands', () => {
     });
 
     it('shows blocked state when required artifacts are missing', async () => {
-      // Only create proposal - missing tasks (required by spec-driven apply block)
+      // Only create proposal - missing specs and tasks (required by spec-driven apply block)
       await createTestChange('blocked-apply', ['proposal']);
 
       const result = await runCLI(['instructions', 'apply', '--change', 'blocked-apply'], {
         cwd: tempDir,
       });
-      expect(result.exitCode).toBe(0);
+      expect(result.exitCode).toBe(1);
       expect(result.stdout).toContain('Blocked');
-      expect(result.stdout).toContain('Missing artifacts: tasks');
+      expect(result.stdout).toContain('Missing artifacts: specs, tasks');
+    });
+
+    it('blocks apply when tasks exist but delta specs are missing', async () => {
+      await createTestChange('missing-specs-apply', ['proposal', 'design', 'tasks']);
+
+      const result = await runCLI(
+        ['instructions', 'apply', '--change', 'missing-specs-apply', '--json'],
+        { cwd: tempDir }
+      );
+      expect(result.exitCode).toBe(1);
+
+      const json = JSON.parse(result.stdout);
+      expect(json.state).toBe('blocked');
+      expect(json.missingArtifacts).toEqual(['specs']);
+      expect(json.instruction).toContain('Delta specs must exist');
     });
 
     it('outputs JSON for apply instructions', async () => {
@@ -568,7 +583,7 @@ apply:
     });
 
     it('spec-driven schema uses apply block configuration', async () => {
-      // Verify that spec-driven schema uses its apply block (requires: [tasks])
+      // Verify that spec-driven schema uses its apply block (requires: [specs, tasks])
       await createTestChange('apply-config-test', ['proposal', 'design', 'specs', 'tasks']);
 
       const result = await runCLI(
@@ -578,7 +593,6 @@ apply:
       expect(result.exitCode).toBe(0);
 
       const json = JSON.parse(result.stdout);
-      // spec-driven schema has apply block with requires: [tasks], so should be ready
       expect(json.schemaName).toBe('spec-driven');
       expect(json.state).toBe('ready');
     });
@@ -624,7 +638,7 @@ artifacts:
           env: { XDG_DATA_HOME: userDataDir },
         }
       );
-      expect(result.exitCode).toBe(0);
+      expect(result.exitCode).toBe(1);
 
       const json = JSON.parse(result.stdout);
       // Without apply block, fallback requires ALL artifacts - second is missing
diff --git a/test/fixtures/tmp-init/openspec/changes/c1/tasks.md b/test/fixtures/tmp-init/openspec/changes/c1/tasks.md
new file mode 100644
index 000000000..de1871bff
--- /dev/null
+++ b/test/fixtures/tmp-init/openspec/changes/c1/tasks.md
@@ -0,0 +1,3 @@
+## 1. Implementation
+
+- [ ] 1.1 Complete the change
\ No newline at end of file