diff --git a/.buildkite/amd/test-amd-merge.yml b/.buildkite/amd/test-amd-merge.yml
index 6ee36de48..1e3e852e9 100644
--- a/.buildkite/amd/test-amd-merge.yml
+++ b/.buildkite/amd/test-amd-merge.yml
@@ -138,7 +138,9 @@ steps:
       mirror_hardwares: [amdproduction]
       grade: Blocking
       commands:
-        - timeout 30m pytest -s -v tests/e2e/offline_inference/test_z_image.py
+        # A cold Z-Image run spends about six minutes loading weights before
+        # the first-request AITER compilation, which can itself exceed 23m.
+        - timeout 55m pytest -s -v tests/e2e/offline_inference/test_z_image.py
 
     - label: "Diffusion GPU Worker Test"
       agent_pool: mi300_2
diff --git a/tests/buildkite/test_amd_pipeline.py b/tests/buildkite/test_amd_pipeline.py
index 36df7ac3e..e7c428dd1 100644
--- a/tests/buildkite/test_amd_pipeline.py
+++ b/tests/buildkite/test_amd_pipeline.py
@@ -67,6 +67,13 @@ def test_ready_diffusion_cpu_suite_is_sharded() -> None:
     assert "--shard-id=$$BUILDKITE_PARALLEL_JOB" in pytest_command
 
 
+def test_z_image_merge_timeout_covers_cold_aiter_compile() -> None:
+    step = _find_step("Diffusion Model Test")
+    pytest_command = next(command for command in step["commands"] if "test_z_image.py" in command)
+
+    assert split(pytest_command)[:2] == ["timeout", "55m"]
+
+
 def test_cosyvoice_ready_smoke_uses_sdpa() -> None:
     step = _find_step("CosyVoice3-TTS E2E Smoke (SDPA)", AMD_READY_PIPELINE)