diff --git a/tests/testthat/test-add_command.R b/tests/testthat/test-add_command.R
new file mode 100644
index 0000000..d3ff145
--- /dev/null
+++ b/tests/testthat/test-add_command.R
@@ -0,0 +1,15 @@
+context("User-defined commands")
+
+test_that("Adding user commands works", {
+    nsenv <- getNamespace('ado')
+    pkgenv <- as.environment('package:ado')
+
+    cmd <- function(expression) { return(as.character(expression)) }
+
+    expect_false('testprint' %in% ls(envir=nsenv))
+
+    ado(string='addCommand cmd, newname(testprint)')
+
+    expect_true('ado_cmd_testprint' %in% ls(envir=nsenv &&
+                'ado_cmd_testprint' %not_in% ls(envir=pkgenv)))
+})