diff --git a/bin/docker/rails b/bin/docker/rails
index 74b3e211034..1c35b782123 100755
--- a/bin/docker/rails
+++ b/bin/docker/rails
@@ -5,5 +5,6 @@ if [[ $# = 1 ]] && [[ "$1" =~ "s" ]];
 then
   PARAMS="$PARAMS -b 0.0.0.0"
 fi
-CMD="cd /src && RACK_HANDLER=puma RAILS_ENV=${RAILS_ENV:=development} rails $PARAMS"
+
+CMD="cd /src && RUBY_GLOBAL_METHOD_CACHE_SIZE=131072 LD_PRELOAD=/usr/lib/libjemalloc.so RACK_HANDLER=puma RAILS_ENV=${RAILS_ENV:=development} rails $PARAMS"
 docker exec -it -u discourse:discourse discourse_dev /bin/bash -c "$CMD"
diff --git a/bin/docker/rake b/bin/docker/rake
index 92abb3546b5..d70b45d7659 100755
--- a/bin/docker/rake
+++ b/bin/docker/rake
@@ -1,5 +1,5 @@
 #!/bin/bash
 
 PARAMS="$@"
-CMD="cd /src && RAILS_ENV=${RAILS_ENV:=development} rake $PARAMS"
+CMD="cd /src && RUBY_GLOBAL_METHOD_CACHE_SIZE=131072 LD_PRELOAD=/usr/lib/libjemalloc.so RAILS_ENV=${RAILS_ENV:=development} rake $PARAMS"
 docker exec -it -u discourse:discourse discourse_dev /bin/bash -c "$CMD"