diff --git a/mcp-config/install.sh b/mcp-config/install.sh
index fe3c633..8bbcb2e 100755
--- a/mcp-config/install.sh
+++ b/mcp-config/install.sh
@@ -120,11 +120,23 @@ say "Key stored at $KEYFILE (0600)."
 # bootstrap run — and then models and skills silently vanish, because sync.sh
 # never runs and OPENCODE_CONFIG is never exported. ~/.zshrc.local is the
 # unmanaged file the managed zshrc sources last, so the hook persists.
-case "${SHELL:-}" in
-  *zsh) RC="$HOME/.zshrc.local" ;;
-  *bash) RC="$HOME/.bashrc" ;;
-  *) [ -f "$HOME/.zshrc" ] && RC="$HOME/.zshrc.local" || RC="$HOME/.bashrc" ;;
-esac
+#
+# Do NOT pick the file from $SHELL alone. On a fresh box bootstrap runs this
+# from the user's ORIGINAL shell: zsh/ has just switched the login shell to zsh,
+# but $SHELL in this process still says bash. The hook then went into ~/.bashrc,
+# below zsh/'s auto-exec hook, so every new terminal exec'd into zsh before
+# reaching it, zsh never sourced sync.sh, and opencode came up unconfigured.
+# The dotfiles-managed ~/.zshrc (or zsh as the account's login shell) wins.
+_login_shell="$(getent passwd "$(id -un)" 2>/dev/null | cut -d: -f7)"
+if grep -qs 'Managed by dotfiles/zsh/install.sh' "$HOME/.zshrc"; then
+  RC="$HOME/.zshrc.local"
+else
+  case "${_login_shell:-${SHELL:-}}" in
+    *zsh) RC="$HOME/.zshrc.local" ;;
+    *bash) RC="$HOME/.bashrc" ;;
+    *) [ -f "$HOME/.zshrc" ] && RC="$HOME/.zshrc.local" || RC="$HOME/.bashrc" ;;
+  esac
+fi
 touch "$RC"
 # It sits alongside the user's secrets; keep it non-readable by others.
 [ "$RC" = "$HOME/.zshrc.local" ] && chmod 0600 "$RC" 2>/dev/null || true