diff --git a/CHANGES.md b/CHANGES.md
index 4a2f5c441d..a7da30a6a1 100644
--- a/CHANGES.md
+++ b/CHANGES.md
@@ -19,7 +19,7 @@
 * Compiler: Emit index source_map to avoid changing mappings (#1714, #1715)
 * Compiler: improved source map generation (#1716)
 * Runtime: change Sys.os_type on windows (Cygwin -> Win32)
-* Runtime: backtraces are really expensive, they need to be be explicitly
+* Runtime: backtraces are really expensive, they need to be explicitly
   requested at compile time (--enable with-js-error) or at startup (OCAMLRUNPARAM=b=1)
 * Runtime: allow dynlink of precompiled js with separate compilation (#1676)
 * Runtime: reimplement the runtime of weak and ephemeron (#1707)
diff --git a/compiler/bin-js_of_ocaml/cmd_arg.ml b/compiler/bin-js_of_ocaml/cmd_arg.ml
index 58cf490539..c294be23a1 100644
--- a/compiler/bin-js_of_ocaml/cmd_arg.ml
+++ b/compiler/bin-js_of_ocaml/cmd_arg.ml
@@ -130,7 +130,7 @@ let options =
   in
   let no_sourcemap =
     let doc =
-      "Don't generate source map. All other source map related flags will be be ignored."
+      "Don't generate source map. All other source map related flags will be ignored."
     in
     Arg.(value & flag & info [ "no-sourcemap"; "no-source-map" ] ~doc)
   in
@@ -395,7 +395,7 @@ let options_runtime_only =
   in
   let no_sourcemap =
     let doc =
-      "Don't generate source map. All other source map related flags will be be ignored."
+      "Don't generate source map. All other source map related flags will be ignored."
     in
     Arg.(value & flag & info [ "no-sourcemap"; "no-source-map" ] ~doc)
   in
diff --git a/compiler/bin-js_of_ocaml/link.ml b/compiler/bin-js_of_ocaml/link.ml
index 521ab6f70c..f48c333fec 100644
--- a/compiler/bin-js_of_ocaml/link.ml
+++ b/compiler/bin-js_of_ocaml/link.ml
@@ -39,7 +39,7 @@ let options =
   in
   let no_sourcemap =
     let doc =
-      "Don't generate source map. All other source map related flags will be be ignored."
+      "Don't generate source map. All other source map related flags will be ignored."
     in
     Arg.(value & flag & info [ "no-sourcemap"; "no-source-map" ] ~doc)
   in
diff --git a/lib/js_of_ocaml/sys_js.mli b/lib/js_of_ocaml/sys_js.mli
index 0c06137acc..02f146e522 100644
--- a/lib/js_of_ocaml/sys_js.mli
+++ b/lib/js_of_ocaml/sys_js.mli
@@ -54,7 +54,7 @@ val read_file : name:string -> string
 val create_file : name:string -> content:string -> unit
 (** Register a file to a Pseudo Filesystem.
       [create_file ~name ~content] register the file [name] with content [content]
-      so it can be be opened with [open_in name] *)
+      so it can be opened with [open_in name] *)
 
 val update_file : name:string -> content:string -> unit
 (** Update a file in the Pseudo Filesystem.