diff --git a/CHANGES.md b/CHANGES.md
index c47c6c4a..c7c977cf 100644
--- a/CHANGES.md
+++ b/CHANGES.md
@@ -21,6 +21,8 @@ next
 - `-j` now defaults to the number of processing units available rather
   4 (#726, @diml)
 
+- Fix attaching index.mld to documentation (#731, fixes #717 @rgrinberg)
+
 1.0+beta20 (10/04/2018)
 -----------------------
 
diff --git a/src/odoc.ml b/src/odoc.ml
index dccc23d9..50d61f4a 100644
--- a/src/odoc.ml
+++ b/src/odoc.ml
@@ -433,7 +433,8 @@ module Gen (S : sig val sctx : SC.t end) = struct
 
   let check_mlds_no_dupes ~pkg ~mlds =
     match
-      List.map mlds ~f:(fun mld -> (Path.basename mld, mld))
+      List.map mlds ~f:(fun mld ->
+        (Filename.chop_extension (Path.basename mld), mld))
       |> String.Map.of_list
     with
     | Ok m -> m
diff --git a/test/blackbox-tests/gen_tests.ml b/test/blackbox-tests/gen_tests.ml
index 09067372..c6d8e93f 100644
--- a/test/blackbox-tests/gen_tests.ml
+++ b/test/blackbox-tests/gen_tests.ml
@@ -89,12 +89,14 @@ end
 
 let exclusions =
   let open Test in
+  let odoc = make ~external_deps:true ~skip_ocaml:"4.02.3" in
   [ make "js_of_ocaml" ~external_deps:true ~js:true ~env:("NODE", "${bin:node}")
   ; make "github25" ~env:("OCAMLPATH", "./findlib-packages")
-  ; make "odoc" ~external_deps:true ~skip_ocaml:"4.02.3"
-  ; make "multiple-private-libs" ~external_deps:true ~skip_ocaml:"4.02.3"
+  ; odoc "odoc"
+  ; odoc "odoc-unique-mlds"
+  ; odoc "github717-odoc-index"
+  ; odoc "multiple-private-libs"
   ; make "ppx-rewriter" ~skip_ocaml:"4.02.3" ~external_deps:true
-  ; make "odoc-unique-mlds" ~skip_ocaml:"4.02.3" ~external_deps:true
   ; make "output-obj" ~skip_platforms:[Mac; Win] ~skip_ocaml:"<4.06.0"
   ; make "github644" ~external_deps:true
   ; make "private-public-overlap" ~external_deps:true
diff --git a/test/blackbox-tests/jbuild.inc b/test/blackbox-tests/jbuild.inc
index 6f8e371b..1eb4e6a5 100644
--- a/test/blackbox-tests/jbuild.inc
+++ b/test/blackbox-tests/jbuild.inc
@@ -170,6 +170,17 @@
     test-cases/github660
     (progn (run ${exe:cram.exe} -test run.t) (diff? run.t run.t.corrected))))))
 
+(alias
+ ((name github717-odoc-index)
+  (deps
+   ((package jbuilder) (files_recursively_in test-cases/github717-odoc-index)))
+  (action
+   (chdir
+    test-cases/github717-odoc-index
+    (progn
+     (run ${exe:cram.exe} -skip-versions 4.02.3 -test run.t)
+     (diff? run.t run.t.corrected))))))
+
 (alias
  ((name include-loop)
   (deps ((package jbuilder) (files_recursively_in test-cases/include-loop)))
@@ -454,6 +465,7 @@
     (alias github597)
     (alias github644)
     (alias github660)
+    (alias github717-odoc-index)
     (alias include-loop)
     (alias inline_tests)
     (alias installable-dup-private-libs)
diff --git a/test/blackbox-tests/test-cases/github717-odoc-index/hello_world.opam b/test/blackbox-tests/test-cases/github717-odoc-index/hello_world.opam
new file mode 100644
index 00000000..e69de29b
diff --git a/test/blackbox-tests/test-cases/github717-odoc-index/index.mld b/test/blackbox-tests/test-cases/github717-odoc-index/index.mld
new file mode 100644
index 00000000..cf74479e
--- /dev/null
+++ b/test/blackbox-tests/test-cases/github717-odoc-index/index.mld
@@ -0,0 +1 @@
+Test index.
\ No newline at end of file
diff --git a/test/blackbox-tests/test-cases/github717-odoc-index/jbuild b/test/blackbox-tests/test-cases/github717-odoc-index/jbuild
new file mode 100644
index 00000000..d881dec3
--- /dev/null
+++ b/test/blackbox-tests/test-cases/github717-odoc-index/jbuild
@@ -0,0 +1,8 @@
+(jbuild_version 1)
+
+(library
+ ((name hello_world)
+  (public_name hello_world)
+  (libraries ())))
+
+(documentation ())
diff --git a/test/blackbox-tests/test-cases/github717-odoc-index/run.t b/test/blackbox-tests/test-cases/github717-odoc-index/run.t
new file mode 100644
index 00000000..bc867e11
--- /dev/null
+++ b/test/blackbox-tests/test-cases/github717-odoc-index/run.t
@@ -0,0 +1 @@
+  $ jbuilder build @doc