diff --git a/src/rpc/avalanche.cpp b/src/rpc/avalanche.cpp
--- a/src/rpc/avalanche.cpp
+++ b/src/rpc/avalanche.cpp
@@ -614,7 +614,7 @@
             result.pushKV("proofid", delegation.getProofId().ToString());
 
             auto levels = delegation.getLevels();
-            result.pushKV("depth", levels.size());
+            result.pushKV("depth", uint64_t(levels.size()));
 
             UniValue levelsArray(UniValue::VARR);
             for (auto &level : levels) {