diff --git a/test/functional/interface_ipc_mining.py b/test/functional/interface_ipc_mining.py
index 05dc75a532b..268ee91712d 100755
--- a/test/functional/interface_ipc_mining.py
+++ b/test/functional/interface_ipc_mining.py
@@ -165,6 +165,20 @@ class IPCMiningTest(BitcoinTestFramework):
 
         asyncio.run(capnp.run(async_routine()))
 
+    def run_negative_timeout_test(self):
+        """Reproduction (AR-38): a negative waitTipChanged timeout
+        should be treated like zero, not abort a node with runtime checks."""
+        self.log.info("Running waitTipChanged negative timeout test")
+
+        async def async_routine():
+            ctx, mining = await make_mining_ctx(self)
+            blockref = await mining.getTip(ctx)
+            result = (await mining.waitTipChanged(ctx, blockref.result.hash, -1.0)).result
+            assert_equal(result.hash, blockref.result.hash)
+
+        asyncio.run(capnp.run(async_routine()))
+        self.nodes[0].getblockcount()  # node still responds
+
     def run_early_startup_test(self):
         """Make sure mining.createNewBlock safely returns on early startup as
         soon as mining interface is available """
@@ -804,6 +818,7 @@ class IPCMiningTest(BitcoinTestFramework):
         self.default_block_wait_options = self.capnp_modules['mining'].BlockWaitOptions()
         self.default_block_wait_options.timeout = self.default_ipc_timeout
         self.default_block_wait_options.feeThreshold = 1
+        self.run_negative_timeout_test()
         self.run_mining_interface_test()
         self.run_early_startup_test()
         self.run_block_template_test()