--- a/dafny-mode.el
+++ b/dafny-mode.el
@@ -553,7 +553,7 @@ open Dafny buffers."
 
 (flycheck-define-command-checker 'dafny
   "Flycheck checker for the Dafny programming language."
-  :command '("Dafny" (eval (boogie-friends-compute-prover-args)) source-inplace)
+  :command '("dafny" (eval (boogie-friends-compute-prover-args)) source-inplace)
   :error-patterns boogie-friends-error-patterns
   :error-filter #'dafny-error-filter
   :predicate #'dafny-predicate