diff --git a/NEWS.md b/NEWS.md
index 5eb64256..a014d34d 100644
--- a/NEWS.md
+++ b/NEWS.md
@@ -26,6 +26,8 @@
 
 * `webR.installPackages()` now correctly handles both `string` and `string[]` arguments for package names and binary repositories (#437).
 
+* Resolved several syntax highlighting and code completion issues in the webR application.
+
 # webR 0.3.3
 
 ## New features
diff --git a/flake.nix b/flake.nix
index a43d907f..47eb92aa 100644
--- a/flake.nix
+++ b/flake.nix
@@ -26,7 +26,7 @@
             #     cd src; prefetch-npm-deps package-lock.json
             srcNpmDeps = pkgs.fetchNpmDeps {
               src = "${self}/src";
-              hash = "sha256-Qb3A25+y6X2Ky0qznfJHPjubkziYcESntXsF7wyDw1w=";
+              hash = "sha256-x8eIcRezS58dDDj6gxNFvFjnad2L3snxVWgnj2CLTHw=";
             };
 
             inherit system;
diff --git a/src/package-lock.json b/src/package-lock.json
index 8be588db..85e51b73 100644
--- a/src/package-lock.json
+++ b/src/package-lock.json
@@ -17,6 +17,7 @@
         "classnames": "^2.2.6",
         "codemirror": "^6.0.1",
         "codemirror-lang-r": "^0.1.0-2",
+        "lezer-r": "^0.1.1",
         "lightningcss": "^1.21.5",
         "prop-types": "^15.7.2",
         "react": "^18.2.0",
@@ -5557,9 +5558,9 @@
       }
     },
     "node_modules/lezer-r": {
-      "version": "0.1.0-5",
-      "resolved": "https://registry.npmjs.org/lezer-r/-/lezer-r-0.1.0-5.tgz",
-      "integrity": "sha512-4I2JAhoHyy9sfJq8n7+4jRDEGjO3Wo+qCGUzfTrxEDEI3dpnEqigmxnjMa7MrejpirvenrO0MmsY2gtbxkQeLg==",
+      "version": "0.1.1",
+      "resolved": "https://registry.npmjs.org/lezer-r/-/lezer-r-0.1.1.tgz",
+      "integrity": "sha512-bIBHtedC6VtdYpsj7q6OO/CiU7rQkNOUJPi3EmqlpxW/Vv/R8jJI6Lr8jRqsSqZZD5GslLsYdrx3mXvvDv3xAg==",
       "dependencies": {
         "@lezer/highlight": "^1.0.0",
         "@lezer/lr": "^1.0.0"
diff --git a/src/package.json b/src/package.json
index a98bb87c..2135e5ba 100644
--- a/src/package.json
+++ b/src/package.json
@@ -63,6 +63,7 @@
     "classnames": "^2.2.6",
     "codemirror": "^6.0.1",
     "codemirror-lang-r": "^0.1.0-2",
+    "lezer-r": "^0.1.1",
     "lightningcss": "^1.21.5",
     "prop-types": "^15.7.2",
     "react": "^18.2.0",
diff --git a/src/repl/components/Editor.tsx b/src/repl/components/Editor.tsx
index 92a98500..4a714c26 100644
--- a/src/repl/components/Editor.tsx
+++ b/src/repl/components/Editor.tsx
@@ -158,7 +158,7 @@ export function Editor({
     if (from === to && !context.explicit) {
       return null;
     }
-    await completionMethods.current.assignLineBuffer(line);
+    await completionMethods.current.assignLineBuffer(line.replace(/\)+$/, ""));
     await completionMethods.current.assignToken(text);
     await completionMethods.current.assignStart(from + 1);
     await completionMethods.current.assignEnd(to + 1);
@@ -168,7 +168,7 @@ export function Editor({
       if (!val) {
         throw new Error('Missing values in completion result.');
       }
-      return { label: val };
+      return { label: val, boost: val.endsWith("=") ? 10 : 0 };
     });
 
     return { from: from, options };