diff --git a/test/blackbox-tests/test-cases/install/install-no-prefix.t b/test/blackbox-tests/test-cases/install/install-no-prefix.t
new file mode 100644
index 00000000000..963311bf543
--- /dev/null
+++ b/test/blackbox-tests/test-cases/install/install-no-prefix.t
@@ -0,0 +1,22 @@
+Here we specify the behaviour of dune install when no install prefix is given.
+
+  $ cat > dune-project << EOF
+  > (lang dune 3.9)
+  > EOF
+
+  $ cat > dune << EOF
+  > (executable
+  >  (public_name main))
+  > EOF
+
+  $ cat > main.ml
+  $ cat > proj.opam
+
+  $ dune build @install
+
+We should suggest to the user here that they should use --prefix.
+
+  $ dune install
+  Error: The mandir installation directory is unknown.
+  Hint: It could be specified with --mandir
+  [1]