1 files changed, 11 insertions, 8 deletions

diff --git a/jstests/libs/logv2_helpers.js b/jstests/libs/logv2_helpers.js
index 0247e6e83d8..68261ed1c89 100644
--- a/jstests/libs/logv2_helpers.js
+++ b/jstests/libs/logv2_helpers.js
@@ -1,26 +1,29 @@
 // logv2_helper.js
 
 function isJsonLogNoConn() {
+    const jsonDefault =
+        getBuildInfo().buildEnvironment.cppdefines.indexOf("MONGO_CONFIG_JSON_LOG_DEFAULT") >= 0;
     if (typeof TestData !== 'undefined' && typeof TestData.logFormat !== 'undefined') {
-        return TestData["logFormat"] == "json";
+        return TestData["logFormat"] == "json" || (jsonDefault && TestData["logFormat"] != "text");
     }
 
-    return false;
+    return jsonDefault;
 }
 
 function isJsonLog(conn) {
+    const jsonDefault =
+        getBuildInfo().buildEnvironment.cppdefines.indexOf("MONGO_CONFIG_JSON_LOG_DEFAULT") >= 0;
+
     if (typeof TestData !== 'undefined' && typeof TestData.logFormat !== 'undefined') {
-        return TestData["logFormat"] == "json";
+        return TestData["logFormat"] == "json" || (jsonDefault && TestData["logFormat"] != "text");
     }
 
     const opts = assert.commandWorked(conn.getDB("admin").runCommand({"getCmdLineOpts": 1}));
-
-    print(tojson(opts));
-
     const parsed = opts["parsed"];
     if (parsed.hasOwnProperty("systemLog") && parsed["systemLog"].hasOwnProperty("logFormat")) {
-        return parsed["systemLog"]["logFormat"] == "json";
+        return parsed["systemLog"]["logFormat"] == "json" ||
+            (jsonDefault && parsed["systemLog"]["logFormat"] != "text");
     }
 
-    return false;
+    return jsonDefault;
 }