diff --git a/src/chainparamsbase.h b/src/chainparamsbase.h
--- a/src/chainparamsbase.h
+++ b/src/chainparamsbase.h
@@ -24,13 +24,20 @@
 
     const std::string &DataDir() const { return strDataDir; }
     int RPCPort() const { return nRPCPort; }
+    uint16_t OnionServiceTargetPort() const {
+        return m_onion_service_target_port;
+    }
 
     CBaseChainParams() = delete;
-    CBaseChainParams(const std::string &data_dir, int rpc_port)
-        : nRPCPort(rpc_port), strDataDir(data_dir) {}
+    CBaseChainParams(const std::string &data_dir, int rpc_port,
+                     uint16_t onion_service_target_port)
+        : nRPCPort(rpc_port),
+          m_onion_service_target_port(onion_service_target_port),
+          strDataDir(data_dir) {}
 
 private:
     int nRPCPort;
+    const uint16_t m_onion_service_target_port;
     std::string strDataDir;
 };
 
diff --git a/src/chainparamsbase.cpp b/src/chainparamsbase.cpp
--- a/src/chainparamsbase.cpp
+++ b/src/chainparamsbase.cpp
@@ -38,18 +38,22 @@
     return *globalChainBaseParams;
 }
 
+/**
+ * Port numbers for incoming Tor connections (8334, 18334, 38334, 18445) have
+ * been chosen arbitrarily to keep ranges of used ports tight.
+ */
 std::unique_ptr<CBaseChainParams>
 CreateBaseChainParams(const std::string &chain) {
     if (chain == CBaseChainParams::MAIN) {
-        return std::make_unique<CBaseChainParams>("", 8332);
+        return std::make_unique<CBaseChainParams>("", 8332, 8334);
     }
 
     if (chain == CBaseChainParams::TESTNET) {
-        return std::make_unique<CBaseChainParams>("testnet3", 18332);
+        return std::make_unique<CBaseChainParams>("testnet3", 18332, 18334);
     }
 
     if (chain == CBaseChainParams::REGTEST) {
-        return std::make_unique<CBaseChainParams>("regtest", 18443);
+        return std::make_unique<CBaseChainParams>("regtest", 18443, 18445);
     }
 
     throw std::runtime_error(