diff --git a/R/read_cargo_metadata.R b/R/read_cargo_metadata.R
index 15fd0eac..4e314c3d 100644
--- a/R/read_cargo_metadata.R
+++ b/R/read_cargo_metadata.R
@@ -26,6 +26,8 @@
 #' }
 #'
 read_cargo_metadata <- function(path = ".") {
+  check_string(path, class = "rextendr_error")
+
   root <- rprojroot::find_package_root_file(path = path)
 
   rust_folder <- normalizePath(