diff --git a/data/built-in-classes b/data/built-in-classes.txt
similarity index 100%
rename from data/built-in-classes
rename to data/built-in-classes.txt
diff --git a/data/built-in-constants b/data/built-in-constants.txt
similarity index 100%
rename from data/built-in-constants
rename to data/built-in-constants.txt
diff --git a/data/built-in-functions b/data/built-in-functions.txt
similarity index 100%
rename from data/built-in-functions
rename to data/built-in-functions.txt
diff --git a/data/built-in-types b/data/built-in-types.txt
similarity index 100%
rename from data/built-in-types
rename to data/built-in-types.txt
diff --git a/data/keywords b/data/keywords.txt
similarity index 100%
rename from data/keywords
rename to data/keywords.txt
diff --git a/gdscript-syntax.el b/gdscript-syntax.el
index 88deceb..11e6077 100644
--- a/gdscript-syntax.el
+++ b/gdscript-syntax.el
@@ -33,14 +33,14 @@ highlighting."
     (insert-file-contents (concat (file-name-directory (or load-file-name buffer-file-name)) file-path))
     (split-string (buffer-string) "\n" t)))
 
-(defvar gdscript-keywords (gdscript--get-package-file-content-as-string "data/keywords"))
-(defvar gdscript-built-in-constants (gdscript--get-package-file-content-as-string "data/built-in-constants"))
+(defvar gdscript-keywords (gdscript--get-package-file-content-as-string "data/keywords.txt"))
+(defvar gdscript-built-in-constants (gdscript--get-package-file-content-as-string "data/built-in-constants.txt"))
 ;; Only contains types that are not classes and that the Godot editor highlights
 ;; like built-in keywords
-(defvar gdscript-built-in-types (gdscript--get-package-file-content-as-string "data/built-in-types"))
-(defvar gdscript-built-in-functions (gdscript--get-package-file-content-as-string "data/built-in-functions"))
+(defvar gdscript-built-in-types (gdscript--get-package-file-content-as-string "data/built-in-types.txt"))
+(defvar gdscript-built-in-functions (gdscript--get-package-file-content-as-string "data/built-in-functions.txt"))
 ;; Contains all engine classes and node types, including vectors, transforms, etc.
-(defvar gdscript-built-in-classes (gdscript--get-package-file-content-as-string "data/built-in-classes"))
+(defvar gdscript-built-in-classes (gdscript--get-package-file-content-as-string "data/built-in-classes.txt"))
 
 (defun regex-maker (words)
   (regexp-opt words 'symbols))