diff --git a/tests/monitoring/minimal.compose.yaml b/tests/monitoring/minimal.compose.yaml
index b663a68..fbd4a5a 100644
--- a/tests/monitoring/minimal.compose.yaml
+++ b/tests/monitoring/minimal.compose.yaml
@@ -1,7 +1,7 @@
 # Test-only services added to examples/monitoring/minimal. None of the example's services change.
 services:
   sink:
-    image: python:3.14.8-alpine
+    image: python:3.15.0-alpine
     command: ["python3", "/sink.py"]
     volumes:
       - "${DOCS_ROOT}/tests/sink.py:/sink.py:ro"
diff --git a/tests/monitoring/receivers.compose.yaml b/tests/monitoring/receivers.compose.yaml
index cc8cf83..01e49bb 100644
--- a/tests/monitoring/receivers.compose.yaml
+++ b/tests/monitoring/receivers.compose.yaml
@@ -8,7 +8,7 @@ services:
       - "127.0.0.1:9093:9093"
 
   sink:
-    image: python:3.14.8-alpine
+    image: python:3.15.0-alpine
     command: ["python3", "/sink.py"]
     volumes:
       - "${DOCS_ROOT}/tests/sink.py:/sink.py:ro"
diff --git a/tests/reverse-proxy/Dockerfile.backend b/tests/reverse-proxy/Dockerfile.backend
index 4e9ae96..a505240 100644
--- a/tests/reverse-proxy/Dockerfile.backend
+++ b/tests/reverse-proxy/Dockerfile.backend
@@ -1,4 +1,4 @@
-FROM python:3.14.8-alpine
+FROM python:3.15.0-alpine
 COPY backend.py /backend.py
 EXPOSE 7681
 CMD ["python3", "-u", "/backend.py"]
diff --git a/tests/reverse-proxy/client.compose.yaml b/tests/reverse-proxy/client.compose.yaml
index f47b01c..9566ac7 100644
--- a/tests/reverse-proxy/client.compose.yaml
+++ b/tests/reverse-proxy/client.compose.yaml
@@ -2,7 +2,7 @@
 # can require that exact address in X-Forwarded-For and in the app's log.
 services:
   client:
-    image: python:3.14.8-alpine
+    image: python:3.15.0-alpine
     command: ["sleep", "infinity"]
     environment:
       AUTH_PASSWORD: "${AUTH_PASSWORD:-}"