diff --git a/src/test/jtx/impl/Env.cpp b/src/test/jtx/impl/Env.cpp
index f5f213710..b9a0660e0 100644
--- a/src/test/jtx/impl/Env.cpp
+++ b/src/test/jtx/impl/Env.cpp
@@ -154,6 +154,9 @@ public:
 Env::AppBundle::AppBundle(beast::unit_test::suite& suite,
     std::unique_ptr<Config> config)
 {
+    using namespace beast::severities;
+    // Use kFatal threshold to reduce noise from STObject.
+    setDebugLogSink (std::make_unique<SuiteSink>("Debug", kFatal, suite));
     auto logs = std::make_unique<SuiteLogs>(suite);
     auto timeKeeper_ =
         std::make_unique<ManualTimeKeeper>();
@@ -163,7 +166,7 @@ Env::AppBundle::AppBundle(beast::unit_test::suite& suite,
     owned = make_Application(std::move(config),
         std::move(logs), std::move(timeKeeper_));
     app = owned.get();
-    app->logs().threshold(beast::severities::kError);
+    app->logs().threshold(kError);
     if(! app->setup())
         Throw<std::runtime_error> ("Env::AppBundle: setup failed");
     timeKeeper->set(
@@ -183,6 +186,9 @@ Env::AppBundle::~AppBundle()
     app->getJobQueue().rendezvous();
     app->signalStop();
     thread.join();
+
+    // Remove the debugLogSink before the suite goes out of scope.
+    setDebugLogSink (nullptr);
 }
 
 //------------------------------------------------------------------------------
diff --git a/src/test/protocol/InnerObjectFormats_test.cpp b/src/test/protocol/InnerObjectFormats_test.cpp
index 442e8a512..f17dc80c5 100644
--- a/src/test/protocol/InnerObjectFormats_test.cpp
+++ b/src/test/protocol/InnerObjectFormats_test.cpp
@@ -24,6 +24,7 @@
 #include <ripple/json/json_reader.h>             // Json::Reader
 #include <ripple/protocol/STParsedJSON.h>        // STParsedJSONObject
 #include <ripple/beast/unit_test.h>
+#include <test/jtx.h>
 
 namespace ripple {
 
@@ -175,6 +176,9 @@ public:
     {
         using namespace InnerObjectFormatsUnitTestDetail;
 
+        // Instantiate a jtx::Env so debugLog writes are exercised.
+        test::jtx::Env env (*this);
+
         for (auto const& test : testArray)
         {
             Json::Value req;
diff --git a/src/test/protocol/STObject_test.cpp b/src/test/protocol/STObject_test.cpp
index fa4518fc3..6dd569d96 100644
--- a/src/test/protocol/STObject_test.cpp
+++ b/src/test/protocol/STObject_test.cpp
@@ -24,6 +24,8 @@
 #include <ripple/json/json_reader.h>
 #include <ripple/json/to_string.h>
 #include <ripple/beast/unit_test.h>
+#include <test/jtx.h>
+
 #include <memory>
 #include <type_traits>
 
@@ -501,6 +503,9 @@ public:
     void
     run()
     {
+        // Instantiate a jtx::Env so debugLog writes are exercised.
+        test::jtx::Env env (*this);
+
         testFields();
         testSerialization();
         testParseJSONArray();