diff --git a/internal/command/fmt.go b/internal/command/fmt.go
index 5451f323e8..3b1320c9b4 100644
--- a/internal/command/fmt.go
+++ b/internal/command/fmt.go
@@ -160,7 +160,7 @@ func (c *FmtCommand) fmt(paths []string, stdin io.Reader, stdout io.Writer, args
 			}
 
 			if !fmtd {
-				diags = diags.Append(fmt.Errorf("Only .tf, .tfvars, and .tftest.hcl files can be processed with tofu fmt"))
+				diags = diags.Append(fmt.Errorf("Only .tf, .tofu, .tfvars, .tftest.hcl, and .tofutest.hcl files can be processed with tofu fmt"))
 				continue
 			}
 		}