diff --git a/src/jbuild.ml b/src/jbuild.ml
index 855b4fc4..b7edadcd 100644
--- a/src/jbuild.ml
+++ b/src/jbuild.ml
@@ -60,7 +60,7 @@ end = struct
       else
         try
           String.iter s ~f:(function
-            | 'A'..'Z' | 'a'..'z' | '_' | '.' | '0'..'9' -> ()
+            | 'A'..'Z' | 'a'..'z' | '_' | '0'..'9' -> ()
             | _ -> raise_notrace Exit);
           s
         with Exit -> invalid ~loc
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 aecbd8de..4d01263b 100644
--- a/test/blackbox-tests/test-cases/no-name-field/run.t
+++ b/test/blackbox-tests/test-cases/no-name-field/run.t
@@ -21,9 +21,6 @@ executable(s) stanza works the same way
 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.
+  File "dune", line 1, characters 22-28:
+  Error: invalid library name
   [1]