diff --git a/justfile b/justfile
index c716dfe..42ee482 100644
--- a/justfile
+++ b/justfile
@@ -51,6 +51,14 @@ cut-version VERSION:
     fi
     mkdir -p versions
     cp -R src "versions/{{VERSION}}"
+    # Freeze the version marker in the snapshot. src/ keeps the literal
+    # `latest (main)` so the rolling /latest/ build stays accurate.
+    sed -i 's|`latest (main)`|`{{VERSION}}`|' "versions/{{VERSION}}/00-overview.md"
+    if ! grep -q '`{{VERSION}}`' "versions/{{VERSION}}/00-overview.md"; then
+        echo "warning: expected version marker not found in 00-overview.md; the" >&2
+        echo "snapshot still says 'latest (main)'. Check that src/00-overview.md" >&2
+        echo "contains the marker line ('**Spec version:** \`latest (main)\`')." >&2
+    fi
     echo "Snapshotted src/ -> versions/{{VERSION}}"
     echo
     echo "Next steps:"
diff --git a/scripts/build-site.sh b/scripts/build-site.sh
index aadf8fe..2cbf3ff 100755
--- a/scripts/build-site.sh
+++ b/scripts/build-site.sh
@@ -30,6 +30,7 @@ mkdir -p "$SITE_DIR"
 
 # ---- latest (from src/) ----
 group "build latest"
+MDBOOK_BOOK__TITLE="MeshCore Protocol Specification — latest (main)" \
 MDBOOK_OUTPUT__HTML__SITE_URL="${SITE_BASE}/latest/" \
     mdbook build "$WORKSPACE" -d "$SITE_DIR/latest"
 endgroup
@@ -51,6 +52,7 @@ for version in $VERSION_DIRS; do
     [ -d "$vdir" ] || continue
     group "build $version"
     if ! MDBOOK_BOOK__SRC="$vdir" \
+         MDBOOK_BOOK__TITLE="MeshCore Protocol Specification — ${version}" \
          MDBOOK_OUTPUT__HTML__SITE_URL="${SITE_BASE}/${version}/" \
          mdbook build "$WORKSPACE" -d "$SITE_DIR/${version}"; then
         warn "mdbook build failed for ${version}; skipping"
diff --git a/src/00-overview.md b/src/00-overview.md
index 39294af..25543f0 100644
--- a/src/00-overview.md
+++ b/src/00-overview.md
@@ -2,6 +2,9 @@
 
 ## Section 0: Overview
 
+**Spec version:** `latest (main)` · see
+[Spec Versions](#spec-versions) for the full list of frozen releases.
+
 ### Status and Provenance
 
 > **This is an unofficial, independent specification.** It is **not** part of
diff --git a/versions/v0.1.0/00-overview.md b/versions/v0.1.0/00-overview.md
index 39294af..1a7a7c4 100644
--- a/versions/v0.1.0/00-overview.md
+++ b/versions/v0.1.0/00-overview.md
@@ -2,6 +2,9 @@
 
 ## Section 0: Overview
 
+**Spec version:** `v0.1.0` · see
+[Spec Versions](#spec-versions) for the full list of frozen releases.
+
 ### Status and Provenance
 
 > **This is an unofficial, independent specification.** It is **not** part of