diff --git a/Snake.nocomments.sh b/Snake.nocomments.sh
index 1087ae8..555ec20 100644
--- a/Snake.nocomments.sh
+++ b/Snake.nocomments.sh
@@ -592,6 +592,7 @@ local unresolved_key_file
 local key_file
 local ignored_key_file
 unresolved_key_file="$1"
+[[ -z "$unresolved_key_file" ]] && return 1
 [[ -v 'priv_keys_files["$unresolved_key_file"]' || ${#priv_keys_files["$unresolved_key_file"]} -gt 0 ]] && return 0
 [[ -v 'key_files["$unresolved_key_file"]' || ${#key_files["$unresolved_key_file"]} -gt 0 ]] && return 1
 key_file="$(${s} readlink -f -- "$unresolved_key_file" 2>/dev/null)"
diff --git a/Snake.sh b/Snake.sh
index b25eaf2..8882917 100755
--- a/Snake.sh
+++ b/Snake.sh
@@ -1012,6 +1012,8 @@ check_and_populate_keys() {
 
   unresolved_key_file="$1"
 
+  [[ -z "$unresolved_key_file" ]] && return 1
+
   # Avoid the readlink call if the path is already absolute.
   [[ -v 'priv_keys_files["$unresolved_key_file"]' || ${#priv_keys_files["$unresolved_key_file"]} -gt 0 ]] && return 0
   [[ -v 'key_files["$unresolved_key_file"]' || ${#key_files["$unresolved_key_file"]} -gt 0 ]] && return 1