diff --git a/.github/workflows/nigiri-infra.yml b/.github/workflows/nigiri-infra.yml
index 5e6285d..8d5308a 100644
--- a/.github/workflows/nigiri-infra.yml
+++ b/.github/workflows/nigiri-infra.yml
@@ -32,6 +32,47 @@ jobs:
         uses: vulpemventures/nigiri-github-action@v1
         with:
           use_liquid: false
+      - name: Wait for Bitcoin RPC
+        run: |
+          python3 - <<'PY'
+          import json
+          import time
+          import urllib.error
+          import urllib.request
+
+          url = "http://localhost:18443"
+          password_mgr = urllib.request.HTTPPasswordMgrWithDefaultRealm()
+          password_mgr.add_password(None, url, "admin1", "123")
+          opener = urllib.request.build_opener(
+              urllib.request.HTTPBasicAuthHandler(password_mgr)
+          )
+          payload = json.dumps({
+              "jsonrpc": "2.0",
+              "id": "ci-ready",
+              "method": "getblockchaininfo",
+              "params": [],
+          }).encode()
+
+          deadline = time.time() + 120
+          last_error = None
+          while time.time() < deadline:
+              try:
+                  request = urllib.request.Request(
+                      url,
+                      data=payload,
+                      headers={"content-type": "application/json"},
+                  )
+                  with opener.open(request, timeout=5) as response:
+                      result = json.loads(response.read())["result"]
+                  print("Bitcoin RPC ready:", result["chain"], result["blocks"])
+                  raise SystemExit(0)
+              except Exception as exc:
+                  last_error = exc
+                  print("Waiting for Bitcoin RPC:", exc)
+                  time.sleep(2)
+
+          raise SystemExit(f"Bitcoin RPC did not become ready: {last_error}")
+          PY
       - name: Run integration tests
         run: |
           pytest tests/integration/basics.py
diff --git a/pyproject.toml b/pyproject.toml
index 64fcf0a..bb92bb2 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -54,5 +54,6 @@ test = [
   "mock",
   "black",
   "pre-commit",
-  "bdkpython"
-]
\ No newline at end of file
+  "Werkzeug<3",
+  "bdkpython==0.32.1"
+]
diff --git a/requirements.txt b/requirements.txt
index b236612..f3a2a8f 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,5 +1,5 @@
 embit>=0.6.1
-Flask>=2.1.1
+Flask>=2.1.1,<2.3
 Flask-SQLAlchemy==2.5.1
 sqlalchemy>=1.4.42,<2.0
 psycopg2-binary
diff --git a/src/cryptoadvance/spectrum/util_specter.py b/src/cryptoadvance/spectrum/util_specter.py
index 462072d..4d4effa 100644
--- a/src/cryptoadvance/spectrum/util_specter.py
+++ b/src/cryptoadvance/spectrum/util_specter.py
@@ -295,7 +295,9 @@ def trace_call_after(cls, url, payload, timestamp):
     def __getattr__(self, method):
         def fn(*args, **kwargs):
             r = self.multi([(method, *args)], **kwargs)[0]
-            if r["error"] is not None:
+            # Bitcoin Core 30.0 omits the JSON-RPC "error" field from successful
+            # responses instead of returning "error": null.
+            if r.get("error") is not None:
                 raise Exception(
                     f"Request error for method {method}{args}: {r['error']['message']}",
                     r,
diff --git a/tests/integration/elsock_test.py b/tests/integration/elsock_test.py
index 6788b7e..5b5dbde 100644
--- a/tests/integration/elsock_test.py
+++ b/tests/integration/elsock_test.py
@@ -35,7 +35,7 @@ def callback(something):
         port=50002,
         callback=callback,
         use_ssl=True,
-        call_timeout=1,
+        call_timeout=10,
     )
     ts = elsock.ping()
     logger.info(f"First working ping in {ts} ms")
@@ -80,7 +80,7 @@ def callback(something):
     logger.info(elsock._socket)
     ts = elsock.ping()
     logger.info(f"second working ping in {ts} ms")
-    assert ts < 1
+    assert ts < 10
     assert caplog.text.count("ElectrumSocket Status changed") == 9
 
     assert (