diff --git a/doc/docker/fpm/entrypoint.sh b/doc/docker/fpm/entrypoint.sh
index e10cadb509..2af20757f3 100755
--- a/doc/docker/fpm/entrypoint.sh
+++ b/doc/docker/fpm/entrypoint.sh
@@ -1,8 +1,16 @@
 #!/bin/bash
 set -e
 
+# if EGW_APC_SHM_SIZE is set in environment, propagate value to apcu.ini
+test -n "$EGW_APC_SHM_SIZE" && {
+  grep "apc.shm_size" /etc/php/7.3/fpm/conf.d/20-apcu.ini >/dev/null && \
+    sed -e "s/^;\?apc.shm_size.*/apc.shm_size=$EGW_APC_SHM_SIZE/g" \
+      -i /etc/php/7.3/fpm/conf.d/20-apcu.ini || \
+    echo "apc.shm_size=$EGW_APC_SHM_SIZE" >> /etc/php/7.3/fpm/conf.d/20-apcu.ini \
+}
+
 # if EGW_SESSION_TIMEOUT is set in environment, propagate value to php.ini
-test -n "$EGW_SESSION_TIMEOUT" && test "$EGW_SESSION_TIMEOUT" -ge 1440 &&
+test -n "$EGW_SESSION_TIMEOUT" && test "$EGW_SESSION_TIMEOUT" -ge 1440 && \
 	sed -e "s/^;\?session.gc_maxlifetime.*/session.gc_maxlifetime=$EGW_SESSION_TIMEOUT/g" \
 		-i /etc/php/7.3/fpm/php.ini