diff --git a/Dockerfile b/Dockerfile
index ea58f6b..72154f0 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -5,7 +5,9 @@ RUN apk add --no-cache libpng libpng-dev libjpeg-turbo-dev libwebp-dev zlib-dev
         && docker-php-ext-configure gd \
         && docker-php-ext-install gd
 
-RUN pecl install redis-5.1.1 \
-    && docker-php-ext-enable redis
+RUN apk add --no-cache autoconf \
+    && pecl install redis-5.1.1 \
+    && docker-php-ext-enable redis \
+    && apk del autoconf
 
 RUN curl -sS https://getcomposer.org/installer | php -- --install-dir=/usr/local/bin --filename=composer