diff --git a/pkgs/development/tools/parsing/tree-sitter/grammars/grammar-sources.nix b/pkgs/development/tools/parsing/tree-sitter/grammars/grammar-sources.nix
index 1a9eeb4a3a40..814c7cf79b50 100644
--- a/pkgs/development/tools/parsing/tree-sitter/grammars/grammar-sources.nix
+++ b/pkgs/development/tools/parsing/tree-sitter/grammars/grammar-sources.nix
@@ -2246,10 +2246,10 @@
   };
 
   rescript = {
-    version = "5.0.0-unstable-2025-03-03";
+    version = "6.0.0-unstable-2026-04-26";
     url = "github:rescript-lang/tree-sitter-rescript";
-    rev = "d2df8a285fff95de56a91d2f8152aeceb66f40ef";
-    hash = "sha256-yNZrihl4BNvLu0Zqr4lSqvdZCeXU3KnCY7ZYC1U42R0=";
+    rev = "5b90cd4e4138b1231a67977303bda47eb608480a";
+    hash = "sha256-f5/z566/Ez8+jzQSXoWkEK3LJGYjWupQw+BFPDyOxsE=";
     meta = {
       license = lib.licenses.mit;
       maintainers = with lib.maintainers; [