diff --git a/html/elements/link.json b/html/elements/link.json
index 7435f54bb87bf6..88b77fed6b022b 100644
--- a/html/elements/link.json
+++ b/html/elements/link.json
@@ -766,7 +766,14 @@
                 "chrome_android": "mirror",
                 "edge": "mirror",
                 "firefox": {
-                  "version_added": false,
+                  "version_added": "145",
+                  "flags": [
+                    {
+                      "type": "preference",
+                      "name": "network.http.dictionaries.enable",
+                      "value_to_set": "true"
+                    }
+                  ],
                   "impl_url": "https://bugzil.la/1918013"
                 },
                 "firefox_android": "mirror",
diff --git a/http/headers/Accept-Encoding.json b/http/headers/Accept-Encoding.json
index 4402c50a4f7541..e22e6eadc83a1d 100644
--- a/http/headers/Accept-Encoding.json
+++ b/http/headers/Accept-Encoding.json
@@ -98,7 +98,14 @@
               "chrome_android": "mirror",
               "edge": "mirror",
               "firefox": {
-                "version_added": false,
+                "version_added": "145",
+                "flags": [
+                  {
+                    "type": "preference",
+                    "name": "network.http.dictionaries.enable",
+                    "value_to_set": "true"
+                  }
+                ],
                 "impl_url": "https://bugzil.la/1917963"
               },
               "firefox_android": "mirror",
@@ -134,7 +141,14 @@
               "chrome_android": "mirror",
               "edge": "mirror",
               "firefox": {
-                "version_added": false,
+                "version_added": "145",
+                "flags": [
+                  {
+                    "type": "preference",
+                    "name": "network.http.dictionaries.enable",
+                    "value_to_set": "true"
+                  }
+                ],
                 "impl_url": "https://bugzil.la/1917963"
               },
               "firefox_android": "mirror",
diff --git a/http/headers/Available-Dictionary.json b/http/headers/Available-Dictionary.json
index 549c465e3f5e8a..0d8323592fdbc6 100644
--- a/http/headers/Available-Dictionary.json
+++ b/http/headers/Available-Dictionary.json
@@ -15,7 +15,14 @@
             "chrome_android": "mirror",
             "edge": "mirror",
             "firefox": {
-              "version_added": false,
+              "version_added": "145",
+              "flags": [
+                {
+                  "type": "preference",
+                  "name": "network.http.dictionaries.enable",
+                  "value_to_set": "true"
+                }
+              ],
               "impl_url": "https://bugzil.la/1917974"
             },
             "firefox_android": "mirror",
diff --git a/http/headers/Content-Encoding.json b/http/headers/Content-Encoding.json
index e54d37568bef36..47c5aca3861e29 100644
--- a/http/headers/Content-Encoding.json
+++ b/http/headers/Content-Encoding.json
@@ -98,7 +98,14 @@
               "chrome_android": "mirror",
               "edge": "mirror",
               "firefox": {
-                "version_added": false,
+                "version_added": "145",
+                "flags": [
+                  {
+                    "type": "preference",
+                    "name": "network.http.dictionaries.enable",
+                    "value_to_set": "true"
+                  }
+                ],
                 "impl_url": "https://bugzil.la/1917965"
               },
               "firefox_android": "mirror",
@@ -134,7 +141,14 @@
               "chrome_android": "mirror",
               "edge": "mirror",
               "firefox": {
-                "version_added": false,
+                "version_added": "145",
+                "flags": [
+                  {
+                    "type": "preference",
+                    "name": "network.http.dictionaries.enable",
+                    "value_to_set": "true"
+                  }
+                ],
                 "impl_url": "https://bugzil.la/1917965"
               },
               "firefox_android": "mirror",
diff --git a/http/headers/Dictionary-ID.json b/http/headers/Dictionary-ID.json
index 6145442ec42fba..d20bae4dd8e838 100644
--- a/http/headers/Dictionary-ID.json
+++ b/http/headers/Dictionary-ID.json
@@ -15,7 +15,14 @@
             "chrome_android": "mirror",
             "edge": "mirror",
             "firefox": {
-              "version_added": false,
+              "version_added": "145",
+              "flags": [
+                {
+                  "type": "preference",
+                  "name": "network.http.dictionaries.enable",
+                  "value_to_set": "true"
+                }
+              ],
               "impl_url": "https://bugzil.la/1917979"
             },
             "firefox_android": "mirror",
diff --git a/http/headers/Use-As-Dictionary.json b/http/headers/Use-As-Dictionary.json
index 612620cabe2ec7..282357b0ff3601 100644
--- a/http/headers/Use-As-Dictionary.json
+++ b/http/headers/Use-As-Dictionary.json
@@ -15,7 +15,14 @@
             "chrome_android": "mirror",
             "edge": "mirror",
             "firefox": {
-              "version_added": false,
+              "version_added": "145",
+              "flags": [
+                {
+                  "type": "preference",
+                  "name": "network.http.dictionaries.enable",
+                  "value_to_set": "true"
+                }
+              ],
               "impl_url": "https://bugzil.la/1917982"
             },
             "firefox_android": "mirror",