diff --git a/e2e-docker/README.md b/e2e-docker/README.md
index f2c9092..ca96aab 100644
--- a/e2e-docker/README.md
+++ b/e2e-docker/README.md
@@ -30,7 +30,8 @@ already-running stack.
   index), rpm (real package + **automatic repodata** generation), npm (stock
   `node:22` client: `npm publish` unscoped + scoped, `npm install` + `require()`,
   second version, republish rejected), gems (stock `ruby:3.3`: `gem push`,
-  `gem install`, `bundle install` + `require`, republish rejected, `gem yank`).
+  `gem install`, `bundle install` + `require`, republish rejected, `gem yank`,
+  yanked re-push rejected).
 - **Virtual repositories** — pypi simple-index merge and helm `index.yaml` merge
   across two members; npm packument merge over two locals via a stock `node:22`
   client (merged versions, install through the member redirect).
diff --git a/e2e-docker/gems_local_test.go b/e2e-docker/gems_local_test.go
index b5f5134..17d1068 100644
--- a/e2e-docker/gems_local_test.go
+++ b/e2e-docker/gems_local_test.go
@@ -13,7 +13,8 @@ import (
 
 // TestLocalGemsPushInstall drives stock gem and bundler clients against a
 // local gems repo: push two versions, reject a republish, gem install and
-// bundle install the latest via the compact index, then yank it.
+// bundle install the latest via the compact index, then yank it and check a
+// re-push of the yanked version with different bytes is rejected.
 func TestLocalGemsPushInstall(t *testing.T) {
 	network := os.Getenv("COMPOSE_NETWORK")
 	internal := os.Getenv("ARTIFACTAPI_INTERNAL")
@@ -31,8 +32,8 @@ func TestLocalGemsPushInstall(t *testing.T) {
 	src := strings.TrimRight(internal, "/") + "/api/v1/local/" + name
 	script := `set -euo pipefail
 export GEM_HOST_API_KEY=unused
-mk() { d=/w/src-$1; mkdir -p $d/lib; cd $d
-  echo "module UnkinE2eHello; VERSION = '$1'; end" > lib/unkin-e2e-hello.rb
+mk() { d=/w/src-$1${2:+-b}; mkdir -p $d/lib; cd $d
+  echo "module UnkinE2eHello; VERSION = '$1'; end${2:-}" > lib/unkin-e2e-hello.rb
   printf 'Gem::Specification.new { |s| s.name = "unkin-e2e-hello"; s.version = "%s"; s.summary = "e2e"; s.authors = ["e2e"]; s.files = ["lib/unkin-e2e-hello.rb"] }' "$1" > g.gemspec
   gem build g.gemspec >/dev/null 2>&1; }
 mk 0.1.0 && gem push --host "$SRC" unkin-e2e-hello-0.1.0.gem
@@ -47,14 +48,18 @@ printf 'source "%s/"\ngem "unkin-e2e-hello"\n' "$SRC" > Gemfile
 bundle install
 bundle exec ruby -e 'require "unkin-e2e-hello"; puts "BUNDLE #{UnkinE2eHello::VERSION}"'
 gem yank unkin-e2e-hello -v 0.2.0 --host "$SRC"
-echo "INFO $(curl -s "$SRC/info/unkin-e2e-hello" | cut -d' ' -f1 | tr '\n' ' ')"`
+echo "INFO $(curl -s "$SRC/info/unkin-e2e-hello" | cut -d' ' -f1 | tr '\n' ' ')"
+mk 0.2.0 '# changed' && if gem push --host "$SRC" unkin-e2e-hello-0.2.0.gem; then echo "yanked re-push accepted"; exit 1; fi
+cd /w/app && gem uninstall -a -x unkin-e2e-hello >/dev/null
+if gem install --remote --no-document unkin-e2e-hello -v 0.2.0; then echo "yanked version installed"; exit 1; fi
+echo "VERSIONS $(curl -s "$SRC/versions" | grep '^unkin-e2e-hello ' | cut -d' ' -f2)"`
 
 	out, err := exec.Command("docker", "run", "--rm", "--network", network,
 		"-e", "SRC="+src, "ruby:3.3", "bash", "-c", script).CombinedOutput()
 	if err != nil {
 		t.Fatalf("gem client run failed: %v\n%s", err, out)
 	}
-	for _, want := range []string{"GEM 0.2.0", "BUNDLE 0.2.0", "INFO --- 0.1.0 "} {
+	for _, want := range []string{"GEM 0.2.0", "BUNDLE 0.2.0", "INFO --- 0.1.0 ", "re-pushing a yanked version is not allowed", "VERSIONS 0.1.0\n"} {
 		if !strings.Contains(string(out), want) {
 			t.Fatalf("missing %q in gem output:\n%s", want, out)
 		}
diff --git a/internal/api/v1/gems.go b/internal/api/v1/gems.go
index ba64927..3ce02b6 100644
--- a/internal/api/v1/gems.go
+++ b/internal/api/v1/gems.go
@@ -26,10 +26,14 @@ import (
 //   gems/<full>.gem                         package (immutable)
 //   quick/Marshal.4.8/<full>.gemspec.rz     marshalled spec (immutable)
 //   _index/<name>/<full>                    compact index /info line; gates visibility
+//   _yanked/<name>/<full>                   yank tombstone; blocks re-push of the version
 
 var gemsMaxPushBytes int64 = 256 << 20
 
-const gemsIndexPrefix = "_index/"
+const (
+	gemsIndexPrefix  = "_index/"
+	gemsYankedPrefix = "_yanked/"
+)
 
 func gemsText(w http.ResponseWriter, status int, msg string) {
 	w.Header().Set("Content-Type", "text/plain; charset=utf-8")
@@ -75,6 +79,15 @@ func (h *ProxyHandler) handleLocalPost(w http.ResponseWriter, r *http.Request) {
 	conflict := func() {
 		gemsText(w, http.StatusConflict, fmt.Sprintf("%s already exists; overwrites are not allowed", full))
 	}
+	yanked, err := h.db.GetLocalFile(r.Context(), remote.Name, gemsYankedPrefix+spec.Name+"/"+full)
+	if err != nil {
+		gemsText(w, http.StatusInternalServerError, err.Error())
+		return
+	}
+	if yanked != nil {
+		gemsText(w, http.StatusConflict, fmt.Sprintf("%s was yanked; re-pushing a yanked version is not allowed", full))
+		return
+	}
 	// The index line gates visibility, so it is written last.
 	for _, f := range []struct {
 		path string
@@ -151,6 +164,16 @@ func (h *ProxyHandler) handleLocalDelete(w http.ResponseWriter, r *http.Request)
 		gemsText(w, http.StatusNotFound, "The version "+spec.Version+" does not exist")
 		return
 	}
+	// The tombstone keeps the yanked line and is written before any delete.
+	line, err := h.readLocalBlob(r.Context(), existing.ContentHash)
+	if err != nil {
+		gemsText(w, http.StatusInternalServerError, err.Error())
+		return
+	}
+	if _, err := h.npmStore(r.Context(), remote.Name, gemsYankedPrefix+spec.Name+"/"+full, line, "text/plain", false); err != nil && !errors.Is(err, database.ErrAlreadyExists) {
+		gemsText(w, http.StatusInternalServerError, err.Error())
+		return
+	}
 	for _, p := range []string{index, "gems/" + full + ".gem", "quick/Marshal.4.8/" + full + ".gemspec.rz"} {
 		if err := h.db.DeleteLocalFile(r.Context(), remote.Name, p); err != nil {
 			gemsText(w, http.StatusInternalServerError, err.Error())
diff --git a/internal/api/v1/gems_handler_test.go b/internal/api/v1/gems_handler_test.go
index 095db07..fcbd6d6 100644
--- a/internal/api/v1/gems_handler_test.go
+++ b/internal/api/v1/gems_handler_test.go
@@ -134,8 +134,26 @@ func TestGemsPushIndexYank(t *testing.T) {
 	if code, _ := npmDo(t, http.MethodGet, base+"gems/hello_gem-0.2.0-java.gem", ""); code != http.StatusNotFound {
 		t.Fatalf("yanked download = %d, want 404", code)
 	}
-	if code, _ := npmDo(t, http.MethodPost, base+"api/v1/gems", string(gj)); code != http.StatusOK {
-		t.Fatalf("push after yank = %d", code)
+	if _, v := npmDo(t, http.MethodGet, base+"versions", ""); strings.Contains(v, "java") || !strings.Contains(v, "hello_gem 0.1.0,0.2.0 ") {
+		t.Fatalf("versions after yank = %q", v)
+	}
+	for _, g := range []string{string(gj), string(gj) + "x"} {
+		if code, body := npmDo(t, http.MethodPost, base+"api/v1/gems", g); code != http.StatusConflict || !strings.Contains(body, "yanked") {
+			t.Fatalf("push after yank = %d %q, want 409", code, body)
+		}
+	}
+	if _, info := npmDo(t, http.MethodGet, base+"info/hello_gem", ""); strings.Contains(info, "java") {
+		t.Fatalf("info after rejected re-push = %q", info)
+	}
+
+	if c := yank("gem_name=hello-gem&version=1.0.0"); c != http.StatusOK {
+		t.Fatalf("yank last version = %d", c)
+	}
+	if code, _ := npmDo(t, http.MethodGet, base+"info/hello-gem", ""); code != http.StatusNotFound {
+		t.Fatalf("info for fully yanked gem = %d, want 404", code)
+	}
+	if _, names := npmDo(t, http.MethodGet, base+"names", ""); names != "---\nhello_gem\n" {
+		t.Fatalf("names after yanking every version = %q", names)
 	}
 }
 
diff --git a/internal/provider/gems/local.go b/internal/provider/gems/local.go
index 6422e8f..0cbb54f 100644
--- a/internal/provider/gems/local.go
+++ b/internal/provider/gems/local.go
@@ -445,10 +445,11 @@ func (m *rbMarshal) requirement(r Requirement) {
 
 // time writes a UTC Time with day resolution, as Time#_dump lays it out.
 func (m *rbMarshal) time(t time.Time) {
-	if t.IsZero() {
-		t = time.Unix(0, 0)
-	}
 	t = t.UTC()
+	// Time#_dump holds year-1900 in 16 bits.
+	if t.IsZero() || t.Year() < 1900 || t.Year() > 1900+0xffff {
+		t = time.Unix(0, 0).UTC()
+	}
 	p := uint32(1)<<31 | uint32(1)<<30 | uint32(t.Year()-1900)<<14 | uint32(t.Month()-1)<<10 | uint32(t.Day())<<5 | uint32(t.Hour())
 	s := uint32(t.Minute())<<26 | uint32(t.Second())<<20
 	m.WriteString("Iu")
diff --git a/internal/provider/gems/local_test.go b/internal/provider/gems/local_test.go
index 9bcf685..4df4f54 100644
--- a/internal/provider/gems/local_test.go
+++ b/internal/provider/gems/local_test.go
@@ -175,6 +175,15 @@ func TestRubyMarshalEncoding(t *testing.T) {
 	if want := "Iu:\x09Time\x0d\x20\xa6\x1f\xc0\x00\x00\x00\x00\x06:\x09zoneI\"\x08UTC\x06:\x06EF"; m.String() != want {
 		t.Errorf("time = %q, want %q", m.String(), want)
 	}
+	var epoch rbMarshal
+	epoch.time(time.Time{})
+	for _, y := range []int{1, 1899, 1900 + 0x10000} {
+		m.Reset()
+		m.time(time.Date(y, 1, 1, 0, 0, 0, 0, time.UTC))
+		if m.String() != epoch.String() {
+			t.Errorf("time(year %d) = %q, want the epoch encoding %q", y, m.String(), epoch.String())
+		}
+	}
 }
 
 func TestQuickSpec(t *testing.T) {