diff --git a/contrib/teamcity/build-configurations.yml b/contrib/teamcity/build-configurations.yml
--- a/contrib/teamcity/build-configurations.yml
+++ b/contrib/teamcity/build-configurations.yml
@@ -161,6 +161,7 @@
 
   build-fuzzer:
     clang: true
+    Werror: true
     cmake_flags:
       - '-DENABLE_SANITIZERS=fuzzer'
     targets:
diff --git a/src/test/fuzz/locale.cpp b/src/test/fuzz/locale.cpp
--- a/src/test/fuzz/locale.cpp
+++ b/src/test/fuzz/locale.cpp
@@ -807,8 +807,6 @@
     const int64_t random_int64 =
         fuzzed_data_provider.ConsumeIntegral<int64_t>();
     const std::string tostring_without_locale = ToString(random_int64);
-    const int32_t random_int32 =
-        fuzzed_data_provider.ConsumeIntegral<int32_t>();
     const std::string strprintf_int_without_locale =
         strprintf("%d", random_int64);
     const double random_double =
diff --git a/test/functional/rpc_deprecated.py b/test/functional/rpc_deprecated.py
--- a/test/functional/rpc_deprecated.py
+++ b/test/functional/rpc_deprecated.py
@@ -4,14 +4,13 @@
 # file COPYING or http://www.opensource.org/licenses/mit-license.php.
 """Test deprecation of RPC calls."""
 from test_framework.test_framework import BitcoinTestFramework
-# from test_framework.util import assert_raises_rpc_error
 
 
 class DeprecatedRpcTest(BitcoinTestFramework):
     def set_test_params(self):
         self.num_nodes = 2
         self.setup_clean_chain = True
-        self.extra_args = [[], []]
+        self.extra_args = [[], ["-deprecatedrpc=banscore"]]
 
     def run_test(self):
         # This test should be used to verify correct behaviour of deprecated
@@ -24,7 +23,10 @@
         # self.log.info("Test generate RPC")
         # assert_raises_rpc_error(-32, 'The wallet generate rpc method is deprecated', self.nodes[0].rpc.generate, 1)
         # self.nodes[1].generate(1)
-        self.log.info("No tested deprecated RPC methods")
+
+        self.log.info("Test deprecated banscore")
+        assert 'banscore' not in self.nodes[0].getpeerinfo()[0]
+        assert 'banscore' in self.nodes[1].getpeerinfo()[0]
 
 
 if __name__ == '__main__':