diff --git a/manifest.yml b/manifest.yml
index 3dad34c8a..bf417410c 100644
--- a/manifest.yml
+++ b/manifest.yml
@@ -220,15 +220,14 @@ dependencies:
   source: https://cache.ruby-lang.org/pub/ruby/3.4/ruby-3.4.7.tar.gz
   source_sha256: 23815a6d095696f7919090fdc3e2f9459b2c83d57224b2e446ce1f5f7333ef36
 - name: rubygems
-  version: 3.6.8
-  uri: https://buildpacks.cloudfoundry.org/dependencies/rubygems/rubygems_3.6.8_linux_noarch_any-stack_7a02eb5e.tgz
-  sha256: 7a02eb5e5cf4ed6ad6a4245babf69f1f4c6acc1cbdf6d126dee8bf73dca7f8de
+  version: 4.0.22
+  uri: https://buildpacks.cloudfoundry.org/dependencies/rubygems/rubygems_4.0.22_linux_noarch_any-stack_b5f29b2f.tgz
+  sha256: b5f29b2f5653d67d6b6319d1fad163b1fa1e3434abfadcfa348d76904b960fbb
   cf_stacks:
   - cflinuxfs4
   - cflinuxfs5
-  - cflinuxfs3
-  source: https://rubygems.org/rubygems/rubygems-3.6.8.tgz
-  source_sha256: da5340b42ba3ddc5ede4a6b948ffa5b409d48cb119e2937e27e4c0b13bf9c390
+  source: https://rubygems.org/rubygems/rubygems-4.0.22.tgz
+  source_sha256: e7e58e5b95156ce7419f7d3b2ae9ecc4f7fe7a4c61a5837f90c507206d8cc226
 - name: yarn
   version: 1.22.22
   uri: https://buildpacks.cloudfoundry.org/dependencies/yarn/yarn_1.22.22_linux_noarch_any-stack_b6132b86.tgz
diff --git a/src/ruby/integration/default_test.go b/src/ruby/integration/default_test.go
index aa370d022..b4c34ba3b 100644
--- a/src/ruby/integration/default_test.go
+++ b/src/ruby/integration/default_test.go
@@ -82,7 +82,13 @@ func testDefault(platform switchblade.Platform, fixtures string) func(*testing.T
 					Execute(name, filepath.Join(fixtures, "default", "vendor_bundle"))
 				Expect(err).NotTo(HaveOccurred())
 
-				Eventually(deployment).Should(Serve(ContainSubstring("Healthy")))
+				// The default 20s Eventually timeout has been observed to
+				// intermittently race with the Docker platform backend
+				// under parallel CI load (container reports started before
+				// the app has actually bound its port). Give this more
+				// headroom, matching the precedent set for the JRuby
+				// fixture (#1140).
+				Eventually(deployment, 90*time.Second, 2*time.Second).Should(Serve(ContainSubstring("Healthy")))
 			})
 		})
 
@@ -95,7 +101,9 @@ func testDefault(platform switchblade.Platform, fixtures string) func(*testing.T
 					Execute(name, filepath.Join(fixtures, "default", "custom_gemfile"))
 				Expect(err).NotTo(HaveOccurred())
 
-				Eventually(deployment).Should(Serve(ContainSubstring("Hello World")))
+				// See the "vendor bundle" test above for why this has an
+				// extended timeout.
+				Eventually(deployment, 90*time.Second, 2*time.Second).Should(Serve(ContainSubstring("Hello World")))
 			})
 		})
 
diff --git a/src/ruby/integration/offline_test.go b/src/ruby/integration/offline_test.go
index b1e204671..bc0505652 100644
--- a/src/ruby/integration/offline_test.go
+++ b/src/ruby/integration/offline_test.go
@@ -3,6 +3,7 @@ package integration_test
 import (
 	"path/filepath"
 	"testing"
+	"time"
 
 	"github.com/cloudfoundry/switchblade"
 	"github.com/sclevine/spec"
@@ -38,7 +39,14 @@ func testOffline(platform switchblade.Platform, fixtures string) func(*testing.T
 				Execute(name, filepath.Join(fixtures, "default", "vendor_cache"))
 			Expect(err).NotTo(HaveOccurred())
 
-			Eventually(deployment).Should(Serve(ContainSubstring("Healthy")))
+			// The default 20s Eventually timeout has been observed to
+			// intermittently race with the Docker platform backend under
+			// parallel CI load: the container reports as started before the
+			// app process inside has actually finished booting and bound
+			// its port, producing a raw "connection refused" at the 20s
+			// mark rather than a graceful retry. Give this more headroom,
+			// matching the precedent set for the JRuby fixture (#1140).
+			Eventually(deployment, 90*time.Second, 2*time.Second).Should(Serve(ContainSubstring("Healthy")))
 		})
 	}
 }