diff --git a/modules/libpref/init/StaticPrefList.yaml b/modules/libpref/init/StaticPrefList.yaml
index 5bbd4976e341..fb7f16282145 100644
--- a/modules/libpref/init/StaticPrefList.yaml
+++ b/modules/libpref/init/StaticPrefList.yaml
@@ -12794,12 +12794,6 @@
   value: false
   mirror: always
 
-# This pref controls whether to use TRRServiceChannel off main thread.
-- name: network.trr.fetch_off_main_thread
-  type: RelaxedAtomicBool
-  value: true
-  mirror: always
-
 # If we should wait for captive portal confirmation before enabling TRR
 - name: network.trr.wait-for-portal
   type: RelaxedAtomicBool
diff --git a/netwerk/dns/TRRService.cpp b/netwerk/dns/TRRService.cpp
index 4599e7b5c0e5..749f736d65c2 100644
--- a/netwerk/dns/TRRService.cpp
+++ b/netwerk/dns/TRRService.cpp
@@ -532,8 +532,7 @@ nsresult TRRService::DispatchTRRRequestInternal(TRR* aTrrRequest,
 }
 
 already_AddRefed<nsIThread> TRRService::MainThreadOrTRRThread(bool aWithLock) {
-  if (!StaticPrefs::network_trr_fetch_off_main_thread() ||
-      XRE_IsSocketProcess() || mDontUseTRRThread) {
+  if (XRE_IsSocketProcess() || mDontUseTRRThread) {
     return do_GetMainThread();
   }
 
diff --git a/netwerk/test/unit/head_trr.js b/netwerk/test/unit/head_trr.js
index 00624e2c96a8..a66cdbc9a015 100644
--- a/netwerk/test/unit/head_trr.js
+++ b/netwerk/test/unit/head_trr.js
@@ -82,7 +82,6 @@ function trr_clear_prefs() {
   Services.prefs.clearUserPref("network.trr.excluded-domains");
   Services.prefs.clearUserPref("network.trr.builtin-excluded-domains");
   Services.prefs.clearUserPref("network.trr.clear-cache-on-pref-change");
-  Services.prefs.clearUserPref("network.trr.fetch_off_main_thread");
   Services.prefs.clearUserPref("captivedetect.canonicalURL");
 
   Services.prefs.clearUserPref("network.http.http2.enabled");
diff --git a/netwerk/test/unit/test_trr_proxy.js b/netwerk/test/unit/test_trr_proxy.js
index 9c1154d7a715..88d80ed40ca9 100644
--- a/netwerk/test/unit/test_trr_proxy.js
+++ b/netwerk/test/unit/test_trr_proxy.js
@@ -109,12 +109,8 @@ async function do_test_pac_dnsResolve() {
 
   trr_test_setup();
 
-  async function test_with(DOMAIN, trrMode, fetchOffMainThread) {
+  async function test_with(DOMAIN, trrMode) {
     Services.prefs.setIntPref("network.trr.mode", trrMode); // TRR first
-    Services.prefs.setBoolPref(
-      "network.trr.fetch_off_main_thread",
-      fetchOffMainThread
-    );
     override.addIPOverride(DOMAIN, "127.0.0.1");
 
     chan = NetUtil.newChannel({
@@ -126,10 +122,8 @@ async function do_test_pac_dnsResolve() {
     await override.clearHostOverride(DOMAIN);
   }
 
-  await test_with("test1.com", 2, true);
-  await test_with("test2.com", 3, true);
-  await test_with("test3.com", 2, false);
-  await test_with("test4.com", 3, false);
+  await test_with("test1.com", 2);
+  await test_with("test2.com", 3);
   await httpserv.stop();
 }
 
diff --git a/netwerk/test/unit/test_trr_proxy_auth.js b/netwerk/test/unit/test_trr_proxy_auth.js
index afd2043d32eb..4a579b2ac262 100644
--- a/netwerk/test/unit/test_trr_proxy_auth.js
+++ b/netwerk/test/unit/test_trr_proxy_auth.js
@@ -11,7 +11,6 @@
 
 function setup() {
   trr_test_setup();
-  Services.prefs.setBoolPref("network.trr.fetch_off_main_thread", true);
 }
 
 setup();