diff --git a/zsh/.zprofile b/zsh/.zprofile
index cdb3446..c09733b 100644
--- a/zsh/.zprofile
+++ b/zsh/.zprofile
@@ -34,6 +34,6 @@ export CALIBRE_USE_SYSTEM_THEME=0
 export CALIBRE_USE_DARK_PALETTE=1
 
 # macOS: homebrew
-eval "$(/opt/homebrew/bin/brew shellenv)"
+[ -f /opt/homebrew/bin/brew ] && eval "$(/opt/homebrew/bin/brew shellenv)"
 
 export PATH
diff --git a/zsh/.zshrc b/zsh/.zshrc
index f407df8..ae24f54 100644
--- a/zsh/.zshrc
+++ b/zsh/.zshrc
@@ -70,6 +70,11 @@ if [[ "$HOST" == core.envs.net ]]; then
 	export GPG_TTY=$(tty)
 fi
 
+# tycho (which is a laptop)
+if [[ "$HOST" == tycho && -z "$DISPLAY" ]]; then
+	export GPG_TTY=$(tty)
+fi
+
 # pash configuration
 export PASH_KEYID=BF66E5C8A1416E2A857C774CA343F43342EB6E2A
 pash() {