diff --git a/gfx/thebes/gfxPrefs.h b/gfx/thebes/gfxPrefs.h
index dcf3077378..bd1b566814 100644
--- a/gfx/thebes/gfxPrefs.h
+++ b/gfx/thebes/gfxPrefs.h
@@ -448,7 +448,9 @@ private:
   DECL_GFX_PREF(Live, "image.mozsamplesize.enabled",           ImageMozSampleSizeEnabled, bool, false);
   DECL_GFX_PREF(Once, "image.multithreaded_decoding.limit",    ImageMTDecodingLimit, int32_t, -1);
   DECL_GFX_PREF(Live, "image.webp.enabled",                    ImageWebPEnabled, bool, true);
+#ifdef MOZ_JXL
   DECL_GFX_PREF(Live, "image.jxl.enabled",                     ImageJXLEnabled, bool, true);
+#endif
 
   DECL_GFX_PREF(Once, "layers.acceleration.enabled",           LayersAccelerationEnabledDoNotUseDirectly, bool, true);
   DECL_GFX_PREF(Live, "layers.acceleration.draw-fps",          LayersDrawFPS, bool, false);
diff --git a/modules/libpref/init/all.js b/modules/libpref/init/all.js
index 8d89c5aea1..c1babf6163 100644
--- a/modules/libpref/init/all.js
+++ b/modules/libpref/init/all.js
@@ -4202,7 +4202,11 @@ pref("image.decode-immediately.enabled", false);
 pref("image.downscale-during-decode.enabled", true);
 
 // The default Accept header sent for images loaded over HTTP(S)
+#ifdef MOZ_JXL
+pref("image.http.accept", "image/webp,image/jxl,image/png,image/*;q=0.8,*/*;q=0.5");
+#else
 pref("image.http.accept", "image/webp,image/png,image/*;q=0.8,*/*;q=0.5");
+#endif
 
 // The threshold for inferring that changes to an <img> element's |src|
 // attribute by JavaScript represent an animation, in milliseconds. If the |src|
@@ -4263,7 +4267,7 @@ pref("image.multithreaded_decoding.limit", -1);
 pref("image.webp.enabled", true);
 
 #ifdef MOZ_JXL
-pref("image.jxl.enabled", false);
+pref("image.jxl.enabled", true);
 #endif
 
 // Limit for the canvas image cache. 0 means we don't limit the size of the