--- a/browser/app/profile/firefox.js
+++ b/browser/app/profile/firefox.js
@@ -1356,17 +1356,21 @@ pref("media.gmp.trial-create.enabled", t
 // plugins list, Firefox will download the GMP/CDM if enabled, and our
 // UI to re-enable EME prompts the user to re-enable EME if it's disabled
 // and script requests EME. If *.visible is false, we won't show the UI
 // to enable the CDM if its disabled; it's as if the keysystem is completely
 // unsupported.
 
 #ifdef MOZ_ADOBE_EME
 pref("media.gmp-eme-adobe.visible", true);
-pref("media.gmp-eme-adobe.enabled", true);
+// When Adobe EME is enabled in the build system, we don't actually enable
+// the plugin by default, so that it doesn't download and install by default.
+// When Adobe EME is first used, Firefox will prompt the user to enable it,
+// and then download the CDM.
+pref("media.gmp-eme-adobe.enabled", false);
 #endif
 
 #ifdef MOZ_WIDEVINE_EME
 pref("media.gmp-widevinecdm.visible", true);
 pref("media.gmp-widevinecdm.enabled", true);
 #endif
 
 // Play with different values of the decay time and get telemetry,