diff --git a/test/runtests.sh b/test/runtests.sh
index 0897221ad..99575c4e6 100755
--- a/test/runtests.sh
+++ b/test/runtests.sh
@@ -80,6 +80,7 @@ mkdir "$PROFILE/zotero"
 cat <<EOF > "$PROFILE/prefs.js"
 user_pref("extensions.autoDisableScopes", 0);
 user_pref("browser.uitour.enabled", false);
+user_pref("browser.shell.checkDefaultBrowser", false);
 user_pref("extensions.zotero.debug.log", $DEBUG);
 user_pref("extensions.zotero.debug.time", $DEBUG);
 user_pref("extensions.zotero.firstRunGuidance", false);