diff --git a/src/ripple/app/misc/ValidatorSite.h b/src/ripple/app/misc/ValidatorSite.h
index 3263aad43..57606066b 100644
--- a/src/ripple/app/misc/ValidatorSite.h
+++ b/src/ripple/app/misc/ValidatorSite.h
@@ -117,6 +117,8 @@ private:
     Application& app_;
     beast::Journal const j_;
 
+    // If both mutex are to be locked at the same time, `sites_mutex_` must be
+    // locked before `state_mutex_` or we may deadlock.
     std::mutex mutable sites_mutex_;
     std::mutex mutable state_mutex_;
 
@@ -201,9 +203,11 @@ private:
         std::lock_guard<std::mutex> const&);
 
     /// Queue next site to be fetched
-    /// lock over state_mutex_ required
+    /// lock over site_mutex_ and state_mutex_ required
     void
-    setTimer(std::lock_guard<std::mutex> const&);
+    setTimer(
+        std::lock_guard<std::mutex> const&,
+        std::lock_guard<std::mutex> const&);
 
     /// request took too long
     void
diff --git a/src/ripple/app/misc/impl/ValidatorSite.cpp b/src/ripple/app/misc/impl/ValidatorSite.cpp
index 946f12f61..7f0af48ad 100644
--- a/src/ripple/app/misc/impl/ValidatorSite.cpp
+++ b/src/ripple/app/misc/impl/ValidatorSite.cpp
@@ -167,9 +167,10 @@ ValidatorSite::load(
 void
 ValidatorSite::start()
 {
-    std::lock_guard lock{state_mutex_};
+    std::lock_guard l0{sites_mutex_};
+    std::lock_guard l1{state_mutex_};
     if (timer_.expires_at() == clock_type::time_point{})
-        setTimer(lock);
+        setTimer(l0, l1);
 }
 
 void
@@ -206,10 +207,10 @@ ValidatorSite::stop()
 }
 
 void
-ValidatorSite::setTimer(std::lock_guard<std::mutex> const& state_lock)
+ValidatorSite::setTimer(
+    std::lock_guard<std::mutex> const& site_lock,
+    std::lock_guard<std::mutex> const& state_lock)
 {
-    std::lock_guard lock{sites_mutex_};
-
     auto next = std::min_element(
         sites_.begin(), sites_.end(), [](Site const& a, Site const& b) {
             return a.nextRefresh < b.nextRefresh;
@@ -531,8 +532,8 @@ ValidatorSite::onSiteFetch(
     detail::response_type&& res,
     std::size_t siteIdx)
 {
+    std::lock_guard lock_sites{sites_mutex_};
     {
-        std::lock_guard lock_sites{sites_mutex_};
         if (endpoint != endpoint_type{})
             sites_[siteIdx].lastRequestEndpoint = endpoint;
         JLOG(j_.debug()) << "Got completion for "
@@ -606,7 +607,7 @@ ValidatorSite::onSiteFetch(
     std::lock_guard lock_state{state_mutex_};
     fetching_ = false;
     if (!stopping_)
-        setTimer(lock_state);
+        setTimer(lock_sites, lock_state);
     cv_.notify_all();
 }
 
@@ -616,8 +617,8 @@ ValidatorSite::onTextFetch(
     std::string const& res,
     std::size_t siteIdx)
 {
+    std::lock_guard lock_sites{sites_mutex_};
     {
-        std::lock_guard lock_sites{sites_mutex_};
         try
         {
             if (ec)
@@ -643,7 +644,7 @@ ValidatorSite::onTextFetch(
     std::lock_guard lock_state{state_mutex_};
     fetching_ = false;
     if (!stopping_)
-        setTimer(lock_state);
+        setTimer(lock_sites, lock_state);
     cv_.notify_all();
 }