diff --git a/pkgs/development/tools/ocaml/merlin/4.x.nix b/pkgs/development/tools/ocaml/merlin/4.x.nix
index fb9b46c00ce5..e55fd630cec9 100644
--- a/pkgs/development/tools/ocaml/merlin/4.x.nix
+++ b/pkgs/development/tools/ocaml/merlin/4.x.nix
@@ -21,23 +21,26 @@ let
     "4.12.1" = "4.7-412";
     "4.13.0" = "4.7-413";
     "4.13.1" = "4.7-413";
-    "4.14.0" = "4.14-414";
-    "4.14.1" = "4.14-414";
-    "4.14.2" = "4.14-414";
+    "4.14.0" = "4.16-414";
+    "4.14.1" = "4.16-414";
+    "4.14.2" = "4.16-414";
     "5.0.0" = "4.14-500";
-    "5.1.0" = "4.14-501";
-    "5.1.1" = "4.14-501";
+    "5.1.0" = "4.16-501";
+    "5.1.1" = "4.16-501";
+    "5.2.0" = "5.1-502";
   };
 
   hashes = {
     "4.7-412" = "sha256-0U3Ia7EblKULNy8AuXFVKACZvGN0arYJv7BWiBRgT0Y=";
     "4.7-413" = "sha256-aVmGWS4bJBLuwsxDKsng/n0A6qlyJ/pnDTcYab/5gyU=";
-    "4.14-414" = "sha256-eQGMyqN8FQHdXE1c94vDQg1kGx6CRDZimBxUctlzmT0=";
     "4.14-500" = "sha256-7CPzJPh1UgzYiX8wPMbU5ZXz1wAJFNQQcp8WuGrR1w4=";
-    "4.14-501" = "sha256-t+npbpJAWMLOQpZCeIqi45ByDUQeIkU4vPSUplIDopI=";
+    "4.16-414" = "sha256-xekZdfPfVoSeGzBvNWwxcJorE519V2NLjSHkcyZvzy0=";
+    "4.16-501" = "sha256-2lvzCbBAZFwpKuRXLMagpwDb0rz8mWrBPI5cODbCHiY=";
+    "5.1-502" = "sha256-T9gIvCaSnP/MqOoGNEeQFZwQ4+r5yRTPRu956Rf8rhU=";
   };
 
   version = lib.getAttr ocaml.version merlinVersions;
+
 in
 
 if !lib.hasAttr ocaml.version merlinVersions
@@ -47,7 +50,6 @@ else
 buildDunePackage {
   pname = "merlin";
   inherit version;
-  duneVersion = "3";
 
   src = fetchurl {
     url = "https://github.com/ocaml/merlin/releases/download/v${version}/merlin-${version}.tbz";
diff --git a/pkgs/development/tools/ocaml/merlin/dot-merlin-reader.nix b/pkgs/development/tools/ocaml/merlin/dot-merlin-reader.nix
index ef30a51a7e6a..28c77b902b4b 100644
--- a/pkgs/development/tools/ocaml/merlin/dot-merlin-reader.nix
+++ b/pkgs/development/tools/ocaml/merlin/dot-merlin-reader.nix
@@ -3,8 +3,6 @@
 buildDunePackage rec {
   pname = "dot-merlin-reader";
 
-  duneVersion = "3";
-
   inherit (merlin) version src;
 
   minimalOCamlVersion = "4.06";