diff --git a/.github/workflows/test-build-deploy.yml b/.github/workflows/test-build-deploy.yml
index 427bea78ed..d82ff817a7 100644
--- a/.github/workflows/test-build-deploy.yml
+++ b/.github/workflows/test-build-deploy.yml
@@ -17,7 +17,7 @@ jobs:
   lint:
     runs-on: ubuntu-24.04
     container:
-      image: quay.io/cortexproject/build-image:master-8b48921f71
+      image: quay.io/cortexproject/build-image:master-7e2dda3451
     steps:
       - name: Checkout Repo
         uses: actions/checkout@8e8c483db84b4bee98b60c0593521ed34d9990e8 # v6.0.1
@@ -57,7 +57,7 @@ jobs:
     name: test (${{ matrix.name }})
     runs-on: ${{ matrix.runner }}
     container:
-      image: quay.io/cortexproject/build-image:master-8b48921f71
+      image: quay.io/cortexproject/build-image:master-7e2dda3451
     steps:
       - name: Checkout Repo
         uses: actions/checkout@8e8c483db84b4bee98b60c0593521ed34d9990e8 # v6.0.1 
@@ -85,7 +85,7 @@ jobs:
     name: test-no-race (${{ matrix.name }})
     runs-on: ${{ matrix.runner }}
     container:
-      image: quay.io/cortexproject/build-image:master-8b48921f71
+      image: quay.io/cortexproject/build-image:master-7e2dda3451
     steps:
       - name: Checkout Repo
         uses: actions/checkout@8e8c483db84b4bee98b60c0593521ed34d9990e8 # v6.0.1
@@ -128,7 +128,7 @@ jobs:
   build:
     runs-on: ubuntu-24.04
     container:
-      image: quay.io/cortexproject/build-image:master-8b48921f71
+      image: quay.io/cortexproject/build-image:master-7e2dda3451
     steps:
       - name: Checkout Repo
         uses: actions/checkout@8e8c483db84b4bee98b60c0593521ed34d9990e8 # v6.0.1
@@ -324,14 +324,14 @@ jobs:
           touch build-image/.uptodate
           MIGRATIONS_DIR=$(pwd)/cmd/cortex/migrations
           echo "Running configs integration tests on ${{ matrix.arch }}"
-          make BUILD_IMAGE=quay.io/cortexproject/build-image:master-8b48921f71 TTY='' configs-integration-test
+          make BUILD_IMAGE=quay.io/cortexproject/build-image:master-7e2dda3451 TTY='' configs-integration-test
 
   deploy_website:
     needs: [build, test, lint]
     if: github.ref == 'refs/heads/master' && github.repository == 'cortexproject/cortex'
     runs-on: ubuntu-24.04
     container:
-      image: quay.io/cortexproject/build-image:master-8b48921f71
+      image: quay.io/cortexproject/build-image:master-7e2dda3451
     steps:
       - name: Checkout Repo
         uses: actions/checkout@8e8c483db84b4bee98b60c0593521ed34d9990e8 # v6.0.1
@@ -373,7 +373,7 @@ jobs:
     if: (github.ref == 'refs/heads/master' || startsWith(github.ref, 'refs/tags/')) && github.repository == 'cortexproject/cortex'
     runs-on: ubuntu-24.04
     container:
-      image: quay.io/cortexproject/build-image:master-8b48921f71
+      image: quay.io/cortexproject/build-image:master-7e2dda3451
     steps:
       - name: Checkout Repo
         uses: actions/checkout@8e8c483db84b4bee98b60c0593521ed34d9990e8 # v6.0.1
diff --git a/Makefile b/Makefile
index 2976e01ec7..b407e50c4d 100644
--- a/Makefile
+++ b/Makefile
@@ -112,7 +112,7 @@ build-image/$(UPTODATE): build-image/*
 SUDO := $(shell docker info >/dev/null 2>&1 || echo "sudo -E")
 BUILD_IN_CONTAINER := true
 BUILD_IMAGE ?= $(IMAGE_PREFIX)build-image
-LATEST_BUILD_IMAGE_TAG ?= master-8b48921f71
+LATEST_BUILD_IMAGE_TAG ?= master-7e2dda3451
 
 # TTY is parameterized to allow Google Cloud Builder to run builds,
 # as it currently disallows TTY devices. This value needs to be overridden
diff --git a/pkg/compactor/shuffle_sharding_grouper.go b/pkg/compactor/shuffle_sharding_grouper.go
index d0b3492ceb..2b4f591836 100644
--- a/pkg/compactor/shuffle_sharding_grouper.go
+++ b/pkg/compactor/shuffle_sharding_grouper.go
@@ -338,7 +338,7 @@ func (g blocksGroup) rangeEndTime() time.Time {
 
 func (g blocksGroup) String() string {
 	out := strings.Builder{}
-	out.WriteString(fmt.Sprintf("Group range start: %d, range end: %d, key %v, blocks: ", g.rangeStart, g.rangeEnd, g.key))
+	fmt.Fprintf(&out, "Group range start: %d, range end: %d, key %v, blocks: ", g.rangeStart, g.rangeEnd, g.key)
 
 	for i, b := range g.blocks {
 		if i > 0 {
@@ -347,7 +347,7 @@ func (g blocksGroup) String() string {
 
 		minT := time.Unix(0, b.MinTime*int64(time.Millisecond)).UTC()
 		maxT := time.Unix(0, b.MaxTime*int64(time.Millisecond)).UTC()
-		out.WriteString(fmt.Sprintf("%s (min time: %s, max time: %s)", b.ULID.String(), minT.String(), maxT.String()))
+		fmt.Fprintf(&out, "%s (min time: %s, max time: %s)", b.ULID.String(), minT.String(), maxT.String())
 	}
 
 	return out.String()
diff --git a/pkg/cortex/cortex.go b/pkg/cortex/cortex.go
index 33e53af873..6591e056c7 100644
--- a/pkg/cortex/cortex.go
+++ b/pkg/cortex/cortex.go
@@ -523,7 +523,7 @@ func (t *Cortex) readyHandler(sm *services.Manager) http.HandlerFunc {
 
 			byState := sm.ServicesByState()
 			for st, ls := range byState {
-				msg.WriteString(fmt.Sprintf("%v: %d\n", st, len(ls)))
+				fmt.Fprintf(&msg, "%v: %d\n", st, len(ls))
 			}
 
 			http.Error(w, msg.String(), http.StatusServiceUnavailable)