diff --git a/.dockerignore b/.dockerignore
index 9fb114c1..870f3610 100644
--- a/.dockerignore
+++ b/.dockerignore
@@ -9,6 +9,7 @@ data/GeoLite2-City*
 data/database.sqlite
 data/shlink-tests.db
 CHANGELOG.md
+CONTRIBUTING.md
 UPGRADE.md
 composer.lock
 vendor
diff --git a/Dockerfile b/Dockerfile
index 5f9bac01..c8d6d988 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -12,13 +12,13 @@ WORKDIR /etc/shlink
 # Install required PHP extensions
 RUN \
     # Temp install dev dependencies needed to compile the extensions
-    apk add --no-cache --virtual .dev-deps sqlite-dev postgresql-dev icu-dev libzip-dev zlib-dev libpng-dev gmp-dev && \
-    docker-php-ext-install -j"$(nproc)" pdo_mysql pdo_pgsql intl calendar sockets bcmath zip gd gmp && \
+    apk add --no-cache --virtual .dev-deps sqlite-dev postgresql-dev icu-dev libzip-dev zlib-dev libpng-dev && \
+    docker-php-ext-install -j"$(nproc)" pdo_mysql pdo_pgsql intl calendar sockets bcmath zip gd && \
     apk add --no-cache sqlite-libs && \
     docker-php-ext-install -j"$(nproc)" pdo_sqlite && \
     # Remove temp dev extensions, and install prod equivalents that are required at runtime
     apk del .dev-deps && \
-    apk add --no-cache postgresql icu libzip libpng gmp
+    apk add --no-cache postgresql icu libzip libpng
 
 # Install sqlsrv driver
 RUN if [ $(uname -m) == "x86_64" ]; then \
diff --git a/data/infra/php.Dockerfile b/data/infra/php.Dockerfile
index 96556869..4fbf676e 100644
--- a/data/infra/php.Dockerfile
+++ b/data/infra/php.Dockerfile
@@ -31,9 +31,6 @@ RUN docker-php-ext-install gd
 RUN apk add --no-cache postgresql-dev
 RUN docker-php-ext-install pdo_pgsql
 
-RUN apk add --no-cache gmp-dev
-RUN docker-php-ext-install gmp
-
 RUN docker-php-ext-install sockets
 RUN docker-php-ext-install bcmath
 
diff --git a/data/infra/swoole.Dockerfile b/data/infra/swoole.Dockerfile
index 570ca2a9..dbaa4202 100644
--- a/data/infra/swoole.Dockerfile
+++ b/data/infra/swoole.Dockerfile
@@ -33,9 +33,6 @@ RUN docker-php-ext-install gd
 RUN apk add --no-cache postgresql-dev
 RUN docker-php-ext-install pdo_pgsql
 
-RUN apk add --no-cache gmp-dev
-RUN docker-php-ext-install gmp
-
 RUN docker-php-ext-install sockets
 RUN docker-php-ext-install bcmath