diff --git a/lib/apache b/lib/apache
index 76eae9c..cf7215b 100644
--- a/lib/apache
+++ b/lib/apache
@@ -290,7 +290,7 @@
         apache_conf=$(apache_site_config_for $name)
         iniset "$file" uwsgi socket "$socket"
         iniset "$file" uwsgi chmod-socket 666
-        echo "ProxyPass \"${url}\" \"unix:${socket}|uwsgi://uwsgi-uds-${name}\" retry=0 " | sudo tee -a $apache_conf
+        echo "ProxyPass \"${url}\" \"unix:${socket}|uwsgi://uwsgi-uds-${name}\" retry=0 acquire=1 " | sudo tee -a $apache_conf
         enable_apache_site $name
         restart_apache_server
     fi
@@ -351,7 +351,7 @@
     apache_conf=$(apache_site_config_for $name)
     echo "KeepAlive Off" | sudo tee $apache_conf
     echo "SetEnv proxy-sendchunked 1" | sudo tee -a $apache_conf
-    echo "ProxyPass \"${url}\" \"http://$APACHE_LOCAL_HOST:$port\" retry=0 " | sudo tee -a $apache_conf
+    echo "ProxyPass \"${url}\" \"http://$APACHE_LOCAL_HOST:$port\" retry=0 acquire=1 " | sudo tee -a $apache_conf
     enable_apache_site $name
     restart_apache_server
 }
@@ -370,7 +370,7 @@
 
     echo "KeepAlive Off" | sudo tee $apache_conf
     echo "SetEnv proxy-sendchunked 1" | sudo tee -a $apache_conf
-    echo "ProxyPass \"${loc}\" \"$url\" retry=0 " | sudo tee -a $apache_conf
+    echo "ProxyPass \"${loc}\" \"$url\" retry=0 acquire=1 " | sudo tee -a $apache_conf
     enable_apache_site $name
     restart_apache_server
 }
diff --git a/lib/tls b/lib/tls
index a1e162d..48e5929 100644
--- a/lib/tls
+++ b/lib/tls
@@ -541,9 +541,11 @@
 
     # Avoid races (at the cost of performance) to re-use a pooled connection
     # where the connection is closed (bug 1807518).
+    # Set acquire=1 to disable waiting for connection pool members so that
+    # we can determine when apache is overloaded (returns 503).
     SetEnv proxy-initial-not-pooled
     <Location />
-        ProxyPass http://$b_host:$b_port/ retry=0 nocanon
+        ProxyPass http://$b_host:$b_port/ retry=0 nocanon acquire=1
         ProxyPassReverse http://$b_host:$b_port/
     </Location>
     ErrorLog $APACHE_LOG_DIR/tls-proxy_error.log