diff --git a/Dockerfile-grocy b/Dockerfile-grocy
index 0bc9e551..c1629af9 100644
--- a/Dockerfile-grocy
+++ b/Dockerfile-grocy
@@ -33,6 +33,7 @@ RUN     apk update && \
 
 # Install system dependencies
 RUN     apk add --no-cache \
+            php7-ctype \
             php7-fpm \
             php7-fileinfo \
             php7-iconv \