diff --git a/test/blackbox-tests/test-cases/no-name-field/public-name-invalid-name/c.opam b/test/blackbox-tests/test-cases/no-name-field/public-name-invalid-name/c.opam
new file mode 100644
index 00000000..e69de29b
diff --git a/test/blackbox-tests/test-cases/no-name-field/public-name-invalid-name/dune b/test/blackbox-tests/test-cases/no-name-field/public-name-invalid-name/dune
new file mode 100644
index 00000000..af6d3200
--- /dev/null
+++ b/test/blackbox-tests/test-cases/no-name-field/public-name-invalid-name/dune
@@ -0,0 +1 @@
+(library (public_name c.find))
\ No newline at end of file
diff --git a/test/blackbox-tests/test-cases/no-name-field/public-name-invalid-name/dune-project b/test/blackbox-tests/test-cases/no-name-field/public-name-invalid-name/dune-project
new file mode 100644
index 00000000..6687faf2
--- /dev/null
+++ b/test/blackbox-tests/test-cases/no-name-field/public-name-invalid-name/dune-project
@@ -0,0 +1 @@
+(lang dune 1.1)
\ No newline at end of file
diff --git a/test/blackbox-tests/test-cases/no-name-field/run.t b/test/blackbox-tests/test-cases/no-name-field/run.t
index e22bf93a..8723a7c6 100644
--- a/test/blackbox-tests/test-cases/no-name-field/run.t
+++ b/test/blackbox-tests/test-cases/no-name-field/run.t
@@ -17,3 +17,13 @@ executable(s) stanza works the same way
   File "dune", line 1, characters 0-36:
   Error: name field may not be omitted before dune version 1.1
   [1]
+
+there's only a public name but it's invalid as a name
+
+  $ dune build --root public-name-invalid-name
+  Entering directory 'public-name-invalid-name'
+      ocamlopt .c.find.objs/c.find.{cmx,o} (exit 2)
+  (cd _build/default && /Users/rgrinberg/.opam/4.06.1/bin/ocamlopt.opt -w @a-4-29-40-41-42-44-45-48-58-59-60-40 -strict-sequence -strict-formats -short-paths -keep-locs -w -49 -g -I .c.find.objs -intf-suffix .ml-gen -no-alias-deps -o .c.find.objs/c.find.cmx -c -impl c.find.ml-gen)
+  File "c.find.ml-gen", line 1:
+  Error: Could not find the .cmi file for interface c.find.ml-gen.
+  [1]