diff --git a/.circleci/config.yml b/.circleci/config.yml
index 60d6a73..274930d 100644
--- a/.circleci/config.yml
+++ b/.circleci/config.yml
@@ -19,7 +19,7 @@ job-references:
   install_dependencies: &install_dependencies
     name: "Install Dependencies"
     command: |
-      sudo apt-get update && sudo apt-get install subversion mariadb-client libfreetype-dev libjpeg62-turbo-dev libpng-dev
+      sudo apt-get update && sudo apt-get install subversion mariadb-client libfreetype-dev libjpeg62-turbo-dev libpng-dev libgmp-dev
       sudo -E docker-php-ext-install mysqli
       sudo -E docker-php-ext-configure gd --with-freetype --with-jpeg
       sudo -E docker-php-ext-install gd