diff --git a/modules/lang/fortran/config.el b/modules/lang/fortran/config.el
index b42e76ad6..f19d9f57f 100644
--- a/modules/lang/fortran/config.el
+++ b/modules/lang/fortran/config.el
@@ -55,7 +55,7 @@
   ;; The `.for' extension is automatically recognized by Emacs and invokes
   ;; `fortran-mode', but not its capital variant `.FOR'. Many old files are
   ;; named the latter way, so we account for that manually here.
-  :mode ("\\.FOR$" . fortran-mode)
+  :mode ("\\.FOR\\'" . fortran-mode)
   :config
   ;; Or else Flycheck will get very mad.
   (setq flycheck-gfortran-language-standard "legacy")
diff --git a/modules/lang/java/config.el b/modules/lang/java/config.el
index 20af39e04..582441398 100644
--- a/modules/lang/java/config.el
+++ b/modules/lang/java/config.el
@@ -47,7 +47,7 @@ If the depth is 2, the first two directories are removed: net.lissner.game.")
 
 
 (use-package! groovy-mode
-  :mode "\\.g\\(?:radle\\|roovy\\)$"
+  :mode "\\.g\\(?:radle\\|roovy\\)\\'"
   :config
   (set-docsets! 'groovy-mode "Groovy" "Groovy_JDK")
   (set-eval-handler! 'groovy-mode "groovy")
diff --git a/modules/lang/php/config.el b/modules/lang/php/config.el
index 6cdda8ded..f38028dd2 100644
--- a/modules/lang/php/config.el
+++ b/modules/lang/php/config.el
@@ -118,7 +118,7 @@
 
 (use-package! hack-mode
   :when (modulep! +hack)
-  :mode "\\.hh$")
+  :mode "\\.hh\\'")
 
 
 (use-package! composer
diff --git a/modules/lang/rust/config.el b/modules/lang/rust/config.el
index e587ac2e6..097649733 100644
--- a/modules/lang/rust/config.el
+++ b/modules/lang/rust/config.el
@@ -9,7 +9,7 @@
 ;;; Packages
 
 (use-package! rustic
-  :mode ("\\.rs$" . rustic-mode)
+  :mode ("\\.rs\\'" . rustic-mode)
   :preface
   ;; HACK `rustic' sets up some things too early. I'd rather disable it and let
   ;;   our respective modules standardize how they're initialized.
diff --git a/modules/tools/ansible/config.el b/modules/tools/ansible/config.el
index f7577a687..1078ca4d7 100644
--- a/modules/tools/ansible/config.el
+++ b/modules/tools/ansible/config.el
@@ -21,7 +21,7 @@
 
 
 (use-package! jinja2-mode
-  :mode "\\.j2$"
+  :mode "\\.j2\\'"
   :config
   ;; The default behavior is to reindent the whole buffer on save. This is
   ;; disruptive and imposing. There are indentation commands available; the user