diff --git a/concourse/loofah-pr.yml b/concourse/loofah-pr.yml
index 87917439..c95d8b4e 100644
--- a/concourse/loofah-pr.yml
+++ b/concourse/loofah-pr.yml
@@ -47,7 +47,6 @@ jobs:
 % RUBIES[:mri].each do |ruby_version|
   - name: ruby-<%= ruby_version %>-pr
     public: true
-    serial_groups: ["ruby-pr"]
     plan:
       - get: ci
       - get: loofah-pr
diff --git a/concourse/loofah-pr.yml.generated b/concourse/loofah-pr.yml.generated
index 47d4e4d2..57b9ce80 100644
--- a/concourse/loofah-pr.yml.generated
+++ b/concourse/loofah-pr.yml.generated
@@ -52,7 +52,6 @@ jobs:
 
   - name: ruby-2.4-pr
     public: true
-    serial_groups: ["ruby-pr"]
     plan:
       - get: ci
       - get: loofah-pr
@@ -80,7 +79,6 @@ jobs:
             status: failure
   - name: ruby-2.5-pr
     public: true
-    serial_groups: ["ruby-pr"]
     plan:
       - get: ci
       - get: loofah-pr
@@ -108,7 +106,6 @@ jobs:
             status: failure
   - name: ruby-2.6-pr
     public: true
-    serial_groups: ["ruby-pr"]
     plan:
       - get: ci
       - get: loofah-pr
@@ -136,7 +133,6 @@ jobs:
             status: failure
   - name: ruby-2.7-pr
     public: true
-    serial_groups: ["ruby-pr"]
     plan:
       - get: ci
       - get: loofah-pr