diff --git a/rust-common.el b/rust-common.el
index b7dd695..ecc5b70 100644
--- a/rust-common.el
+++ b/rust-common.el
@@ -16,5 +16,11 @@
   :type 'function
   :group 'rust-mode)
 
+(defcustom rust-indent-offset 4
+  "Indent Rust code by this number of spaces."
+  :type 'integer
+  :group 'rust-mode
+  :safe #'integerp)
+
 (provide 'rust-common)
 ;;; rust-common.el ends here
diff --git a/rust-prog-mode.el b/rust-prog-mode.el
index 05bc5e0..64c3ed1 100644
--- a/rust-prog-mode.el
+++ b/rust-prog-mode.el
@@ -17,12 +17,6 @@
     ("INFINITY" . ?∞) ("->" . ?→) ("=>" . ?⇒))
   "Alist of symbol prettifications used for `prettify-symbols-alist'.")
 
-(defcustom rust-indent-offset 4
-  "Indent Rust code by this number of spaces."
-  :type 'integer
-  :group 'rust-mode
-  :safe #'integerp)
-
 (defcustom rust-indent-method-chain nil
   "Indent Rust method chains, aligned by the `.' operators."
   :type 'boolean