diff --git a/misc/emacs/nix-mode.el b/misc/emacs/nix-mode.el
index d98353177..9d4d1b894 100644
--- a/misc/emacs/nix-mode.el
+++ b/misc/emacs/nix-mode.el
@@ -76,7 +76,7 @@ The hook `nix-mode-hook' is run when Nix mode is started.
     ("\\<baseNameOf\\>" . font-lock-builtin-face)
     ("\\<toString\\>" . font-lock-builtin-face)
     ("\\<isNull\\>" . font-lock-builtin-face)
-    ("\\<\\([a-zA-Z_][a-zA-Z0-9_']*\\)[ \t]*="
+    ("\\<\\([a-zA-Z_][a-zA-Z0-9_'\.]*\\)[ \t]*="
      (1 font-lock-variable-name-face nil nil))
     ("[a-zA-Z][a-zA-Z0-9\\+-\\.]*:[a-zA-Z0-9%/\\?:@&=\\+\\$,_\\.!~\\*'-]+"
      . font-lock-constant-face)