diff --git a/config/apache/standardebooks.org.conf b/config/apache/standardebooks.org.conf
index 83fbcf66..57ac6af4 100644
--- a/config/apache/standardebooks.org.conf
+++ b/config/apache/standardebooks.org.conf
@@ -127,6 +127,9 @@ Define domain standardebooks.org
 	# PHP-FPM configuration
 	# See https://serverfault.com/questions/450628/apache-2-4-php-fpm-proxypassmatch/510784
 
+	# Required for FPM to receive POST data sent with Transfer-Encoding: chunked
+	SetEnv proxy-sendcl 1
+
 	# Forward all PHP requests to the php-fpm pool for this domain.
 	<FilesMatch \.php$>
 		SetHandler	"proxy:unix:/run/php/${domain}.sock|fcgi://${domain}"
diff --git a/config/apache/standardebooks.test.conf b/config/apache/standardebooks.test.conf
index 176d1ecb..f6eda97b 100644
--- a/config/apache/standardebooks.test.conf
+++ b/config/apache/standardebooks.test.conf
@@ -126,6 +126,9 @@ Define domain standardebooks.test
 	# PHP-FPM configuration
 	# See https://serverfault.com/questions/450628/apache-2-4-php-fpm-proxypassmatch/510784
 
+	# Required for FPM to receive POST data sent with Transfer-Encoding: chunked
+	SetEnv proxy-sendcl 1
+
 	# Forward all PHP requests to the php-fpm pool for this domain.
 	<FilesMatch \.php$>
 		SetHandler	"proxy:unix:/run/php/${domain}.sock|fcgi://${domain}"