diff --git a/R/fit.R b/R/fit.R
index 30e7310a..87b8f648 100644
--- a/R/fit.R
+++ b/R/fit.R
@@ -916,7 +916,8 @@ CmdStanFit$set("public", name = "cmdstan_diagnose", value = cmdstan_diagnose)
 #'
 #' For `$save_metric_files()` everything is the same as for
 #' `$save_output_files()` except `"-metric-"` is included in the new
-#' file name after `basename`.
+#' file name after `basename`. Make sure to set `save_metric=TRUE` when
+#' fitting the model.
 #'
 #' For `$save_config_files()` everything is the same as for
 #' `$save_output_files()` except `"-config-"` is included in the new
diff --git a/R/run.R b/R/run.R
index 9202f0d4..7ffc44b0 100644
--- a/R/run.R
+++ b/R/run.R
@@ -258,6 +258,12 @@ CmdStanRun <- R6::R6Class(
                                  timestamp = TRUE,
                                  random = TRUE) {
       current_files <- self$metric_files(include_failed = TRUE) # used so we get error if 0 files
+      if (is.null(current_files)) {
+        stop(
+          "No metric files found. Make sure to set 'save_metric=TRUE' when fitting the model.",
+          call. = FALSE
+        )
+      }
       new_paths <- copy_temp_files(
         current_paths = current_files,
         new_dir = dir,
diff --git a/man-roxygen/model-sample-args.R b/man-roxygen/model-sample-args.R
index fe4e1014..6ab0abd6 100644
--- a/man-roxygen/model-sample-args.R
+++ b/man-roxygen/model-sample-args.R
@@ -94,5 +94,5 @@
 #' @param save_metric (logical) When `TRUE`, call CmdStan with argument
 #'   `"adaptation save_metric=1"` to save the adapted metric in separate JSON
 #'   file with elements "stepsize", "metric_type" and "inv_metric". The default
-#'   is `TRUE`. This option is only available in CmdStan 2.34.0 and later.
+#'    is `FALSE`. This option is only available in CmdStan 2.34.0 and later.
 #'
diff --git a/man/fit-method-save_output_files.Rd b/man/fit-method-save_output_files.Rd
index beb1e35b..14ef8621 100644
--- a/man/fit-method-save_output_files.Rd
+++ b/man/fit-method-save_output_files.Rd
@@ -109,7 +109,8 @@ file name after \code{basename}.
 
 For \verb{$save_metric_files()} everything is the same as for
 \verb{$save_output_files()} except \code{"-metric-"} is included in the new
-file name after \code{basename}.
+file name after \code{basename}. Make sure to set \code{save_metric=TRUE} when
+fitting the model.
 
 For \verb{$save_config_files()} everything is the same as for
 \verb{$save_output_files()} except \code{"-config-"} is included in the new
diff --git a/man/model-method-sample.Rd b/man/model-method-sample.Rd
index 2558e630..d1c23359 100644
--- a/man/model-method-sample.Rd
+++ b/man/model-method-sample.Rd
@@ -296,7 +296,7 @@ using the \code{\link[=fit-method-summary]{$summary()}} method.}
 \item{save_metric}{(logical) When \code{TRUE}, call CmdStan with argument
 \code{"adaptation save_metric=1"} to save the adapted metric in separate JSON
 file with elements "stepsize", "metric_type" and "inv_metric". The default
-is \code{TRUE}. This option is only available in CmdStan 2.34.0 and later.}
+is \code{FALSE}. This option is only available in CmdStan 2.34.0 and later.}
 
 \item{save_cmdstan_config}{(logical) When \code{TRUE} (the default), call CmdStan
 with argument \code{"output save_config=1"} to save a json file which contains
diff --git a/tests/testthat/test-fit-mcmc.R b/tests/testthat/test-fit-mcmc.R
index 122dc503..ec454c5b 100644
--- a/tests/testthat/test-fit-mcmc.R
+++ b/tests/testthat/test-fit-mcmc.R
@@ -399,3 +399,14 @@ test_that("metadata()$time has chains rowss", {
   expect_equal(nrow(fit_mcmc_2$metadata()$time), fit_mcmc_2$num_chains())
   expect_equal(nrow(fit_mcmc_3$metadata()$time), fit_mcmc_3$num_chains())
 })
+
+test_that("save_metric_files works and has clear error message when no files", {
+  expect_error(
+    fit_mcmc$save_metric_files(),
+    "No metric files found"
+  )
+  fit_save_metric <- testing_fit("logistic", save_metric = TRUE)
+  paths <- fit_save_metric$save_metric_files()
+  checkmate::expect_file_exists(paths, extension = "json")
+  expect_true(all(file.size(paths) > 0))
+})