diff --git a/Dockerfile b/Dockerfile
index cea2681..a9b71b0 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -11,3 +11,7 @@ FROM nextcloud:16
 
 # CMD cron && apache2-foreground
 
+# Mandatory for bookmark extension
+RUN docker-php-ext-configure gmp; \
+      docker-php-ext-install gmp
+