diff --git a/src/test/jtx/Oracle.h b/src/test/jtx/Oracle.h
index 474a003ff87..ac46b32d092 100644
--- a/src/test/jtx/Oracle.h
+++ b/src/test/jtx/Oracle.h
@@ -32,6 +32,12 @@ using AnyValue = std::variant<std::string, double, Json::Int, Json::UInt>;
 using OraclesData =
     std::vector<std::pair<std::optional<Account>, std::optional<AnyValue>>>;
 
+// Special string value, which is converted to unquoted string in the string
+// passed to rpc.
+constexpr char const* NoneTag = "%None%";
+constexpr char const* UnquotedNone = "None";
+constexpr char const* NonePattern = "\"%None%\"";
+
 std::uint32_t
 asUInt(AnyValue const& v);
 
diff --git a/src/test/jtx/impl/Oracle.cpp b/src/test/jtx/impl/Oracle.cpp
index a24540f7326..a6d08e21198 100644
--- a/src/test/jtx/impl/Oracle.cpp
+++ b/src/test/jtx/impl/Oracle.cpp
@@ -176,7 +176,7 @@ Oracle::aggregatePrice(
         toJson(jv[jss::time_threshold], *timeThreshold);
     // Convert "%None%" to None
     auto str = to_string(jv);
-    str = boost::regex_replace(str, boost::regex("\"%None%\""), "None");
+    str = boost::regex_replace(str, boost::regex(NonePattern), UnquotedNone);
     auto jr = env.rpc("json", "get_aggregate_price", str);
 
     if (jr.isObject())
@@ -312,8 +312,8 @@ Oracle::ledgerEntry(
     }
     // Convert "%None%" to None
     auto str = to_string(jvParams);
-    str = boost::regex_replace(str, boost::regex("\"%None%\""), "None");
-    return env.rpc("json", "ledger_entry", to_string(jvParams))[jss::result];
+    str = boost::regex_replace(str, boost::regex(NonePattern), UnquotedNone);
+    return env.rpc("json", "ledger_entry", str)[jss::result];
 }
 
 void
diff --git a/src/test/rpc/GetAggregatePrice_test.cpp b/src/test/rpc/GetAggregatePrice_test.cpp
index 2ec65dac192..1fb263bbc55 100644
--- a/src/test/rpc/GetAggregatePrice_test.cpp
+++ b/src/test/rpc/GetAggregatePrice_test.cpp
@@ -56,7 +56,7 @@ class GetAggregatePrice_test : public beast::unit_test::suite
 
             // invalid base_asset, quote_asset
             std::vector<AnyValue> invalidAsset = {
-                "%None%",
+                NoneTag,
                 1,
                 -1,
                 1.2,
@@ -100,7 +100,7 @@ class GetAggregatePrice_test : public beast::unit_test::suite
             BEAST_EXPECT(ret[jss::error].asString() == "objectNotFound");
             // invalid values
             std::vector<AnyValue> invalidDocument = {
-                "%None%", 1.2, -1, "", "none", "1.2"};
+                NoneTag, 1.2, -1, "", "none", "1.2"};
             for (auto const& v : invalidDocument)
             {
                 ret = Oracle::aggregatePrice(env, "XRP", "USD", {{{owner, v}}});
@@ -131,7 +131,7 @@ class GetAggregatePrice_test : public beast::unit_test::suite
 
             // invalid trim value
             std::vector<AnyValue> invalidTrim = {
-                "%None%", 0, 26, -1, 1.2, "", "none", "1.2"};
+                NoneTag, 0, 26, -1, 1.2, "", "none", "1.2"};
             for (auto const& v : invalidTrim)
             {
                 ret = Oracle::aggregatePrice(
@@ -141,7 +141,7 @@ class GetAggregatePrice_test : public beast::unit_test::suite
 
             // invalid time threshold value
             std::vector<AnyValue> invalidTime = {
-                "%None%", -1, 1.2, "", "none", "1.2"};
+                NoneTag, -1, 1.2, "", "none", "1.2"};
             for (auto const& v : invalidTime)
             {
                 ret = Oracle::aggregatePrice(
diff --git a/src/test/rpc/LedgerRPC_test.cpp b/src/test/rpc/LedgerRPC_test.cpp
index e58d1b69e5d..ee10a1cdd88 100644
--- a/src/test/rpc/LedgerRPC_test.cpp
+++ b/src/test/rpc/LedgerRPC_test.cpp
@@ -2293,7 +2293,7 @@ class LedgerRPC_test : public beast::unit_test::suite
         Oracle oracle(env, {.owner = owner});
 
         // Malformed document id
-        std::vector<AnyValue> invalid = {"%None%", -1, 1.2, "", "Invalid"};
+        std::vector<AnyValue> invalid = {NoneTag, -1, 1.2, "", "Invalid"};
         for (auto const& v : invalid)
         {
             auto const res = Oracle::ledgerEntry(env, owner, v);