diff --git a/conf/firefox-forbidden-policies.js b/conf/firefox-forbidden-policies.js
index a6f7ee9f..8af49025 100644
--- a/conf/firefox-forbidden-policies.js
+++ b/conf/firefox-forbidden-policies.js
@@ -76,10 +76,11 @@ lockPref("privacy.fingerprintingProtection", true);
 // Somehow I cannot clearPref this, so...
 //clearPref("privacy.fingerprintingProtection");
 //lockPref("privacy.fingerprintingProtection", false);
-pref(
+lockPref(
 	"privacy.fingerprintingProtection.overrides",
-	"+AllTargets,-KeyboardEvents,-CSSPrefersColorScheme,-CSSPrefersReducedMotion,-JSDateTimeUTC",
+	"+AllTargets,-KeyboardEvents,-CSSPrefersColorScheme,-CSSPrefersReducedMotion,-JSDateTimeUTC,-FontVisibilityBaseSystem",
 );
+lockPref("browser.display.use_document_fonts", 0);
 //clearPref("privacy.fingerprintingProtection.overrides");
 lockPref("privacy.fingerprintingProtection.pbmode", true);
 //clearPref("privacy.fingerprintingProtection.pbmode");
diff --git a/etc/firefox/policies/policies.json b/etc/firefox/policies/policies.json
index cca46a31..760a2d28 100644
--- a/etc/firefox/policies/policies.json
+++ b/etc/firefox/policies/policies.json
@@ -458,8 +458,8 @@
 				"Value": false
 			},
 			"browser.display.use_document_fonts": {
-				"Comment": "Are webpages allowed to set their own fonts by default? 0 forbids them. See also browser.display.use_document_fonts.icon_font_allowlist for what webpages are allowed to set.",
-				"Status": "user",
+				"Comment": "Are webpages allowed to set their own fonts by default? 0 forbids them. See also browser.display.use_document_fonts.icon_font_allowlist for what webpages are allowed to set. If changing this, see also fingerprinting overrides",
+				"Status": "locked",
 				"Type": "number",
 				"Value": 0
 			},
@@ -831,10 +831,10 @@
 				"Value": true
 			},
 			"privacy.fingerprintingProtection.overrides": {
-				"Comment": "Preference not allowed for stability reasons. :( https://searchfox.org/mozilla-central/source/toolkit/components/resistfingerprinting/RFPTargets.inc",
+				"Comment": "Preference not allowed for stability reasons. :( https://searchfox.org/mozilla-central/source/toolkit/components/resistfingerprinting/RFPTargets.inc - If you adjust this, see also use_document_fonts to not increase fingerprinting surface excessively",
 				"Status": "locked",
 				"Type": "string",
-				"Value": "+AllTargets,-KeyboardEvents,-CSSPrefersColorScheme,-CSSPrefersReducedMotion,-JSDateTimeUTC"
+				"Value": "+AllTargets,-KeyboardEvents,-CSSPrefersColorScheme,-CSSPrefersReducedMotion,-JSDateTimeUTC,-FontVisibilityBaseSystem"
 			},
 			"privacy.fingerprintingProtection.pbmode": {
 				"Comment": "Preference not allowed for stability reasons. :(",