diff --git a/package.json b/package.json
index de899a5617f..f9d26c4cbc1 100644
--- a/package.json
+++ b/package.json
@@ -40,11 +40,11 @@
         "mkdirp": "^0.5.3",
         "resolve": "^1.3.2",
         "semver": "^5.3.0",
-        "tslib": "^1.10.0",
+        "tslib": "^1.13.0",
         "tsutils": "^2.29.0"
     },
     "peerDependencies": {
-        "typescript": ">=2.3.0-dev || >=2.4.0-dev || >=2.5.0-dev || >=2.6.0-dev || >=2.7.0-dev || >=2.8.0-dev || >=2.9.0-dev || >=3.0.0-dev || >= 3.1.0-dev || >= 3.2.0-dev"
+        "typescript": ">=2.3.0-dev || >=2.4.0-dev || >=2.5.0-dev || >=2.6.0-dev || >=2.7.0-dev || >=2.8.0-dev || >=2.9.0-dev || >=3.0.0-dev || >= 3.1.0-dev || >= 3.2.0-dev || >= 4.0.0-dev"
     },
     "devDependencies": {
         "@octokit/rest": "^16.24.3",
@@ -73,7 +73,7 @@
         "tslint-config-prettier": "^1.18.0",
         "tslint-plugin-prettier": "^2.0.1",
         "tslint-test-config-non-relative": "file:test/external/tslint-test-config-non-relative",
-        "typescript": "~3.8.2",
+        "typescript": "~4.0.0-dev.20200722",
         "yarn-deduplicate": "^1.1.1"
     },
     "engines": {
diff --git a/src/rules/alignRule.ts b/src/rules/alignRule.ts
index 36c595f7e83..4bcea581957 100644
--- a/src/rules/alignRule.ts
+++ b/src/rules/alignRule.ts
@@ -142,7 +142,9 @@ class AlignWalker extends Lint.AbstractWalker<Options> {
                     case ts.SyntaxKind.TupleType:
                         if (this.options.elements) {
                             this.checkAlignment(
-                                (node as ts.TupleTypeNode).elementTypes,
+                                // In TS 4 TupleTypeNode.elementTypes has been updated to elements
+                                // tslint:disable-next-line
+                                (node as any).elementTypes || (node as ts.TupleTypeNode).elements,
                                 OPTION_ELEMENTS,
                             );
                         }
diff --git a/src/rules/noRedundantJsdocRule.ts b/src/rules/noRedundantJsdocRule.ts
index 1ed01ddc32a..d30e4d6ec24 100644
--- a/src/rules/noRedundantJsdocRule.ts
+++ b/src/rules/noRedundantJsdocRule.ts
@@ -73,7 +73,7 @@ function walk(ctx: Lint.WalkContext): void {
                     );
                 }
                 break;
-
+            case ts.SyntaxKind.JSDocDeprecatedTag:
             case ts.SyntaxKind.JSDocAugmentsTag:
             case ts.SyntaxKind.JSDocAuthorTag:
                 // OK
diff --git a/src/rules/oneLineRule.ts b/src/rules/oneLineRule.ts
index 02602fabbd1..ef6c4ef7047 100644
--- a/src/rules/oneLineRule.ts
+++ b/src/rules/oneLineRule.ts
@@ -87,7 +87,7 @@ class OneLineWalker extends Lint.AbstractWalker<Options> {
                     if (
                         !isBlockLike(node.parent) ||
                         (node.parent.kind === ts.SyntaxKind.CaseClause &&
-                            (node.parent as ts.CaseClause).statements.length === 1)
+                            node.parent.statements.length === 1)
                     ) {
                         this.check({ pos: node.pos, end: (node as ts.Block).statements.pos });
                     }
diff --git a/yarn.lock b/yarn.lock
index 03cb4497925..324b0fd04ed 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -1822,10 +1822,10 @@ tsconfig@^6.0.0:
     strip-bom "^3.0.0"
     strip-json-comments "^2.0.0"
 
-tslib@^1.10.0, tslib@^1.7.1, tslib@^1.8.0, tslib@^1.8.1:
-  version "1.10.0"
-  resolved "https://registry.yarnpkg.com/tslib/-/tslib-1.10.0.tgz#c3c19f95973fb0a62973fb09d90d961ee43e5c8a"
-  integrity sha512-qOebF53frne81cf0S9B41ByenJ3/IuH8yJKngAX35CmiZySA0khhkovshKK+jGCaMnVomla7gVlIcc3EvKPbTQ==
+tslib@^1.13.0, tslib@^1.7.1, tslib@^1.8.0, tslib@^1.8.1:
+  version "1.13.0"
+  resolved "https://registry.yarnpkg.com/tslib/-/tslib-1.13.0.tgz#c881e13cc7015894ed914862d276436fa9a47043"
+  integrity sha512-i/6DQjL8Xf3be4K/E6Wgpekn5Qasl1usyw++dAA35Ue5orEn65VIxOA+YvNNl9HV3qv70T7CNwjODHZrLwvd1Q==
 
 tslint-config-prettier@^1.18.0:
   version "1.18.0"
@@ -1880,10 +1880,10 @@ type-detect@^1.0.0:
   resolved "https://registry.yarnpkg.com/type-detect/-/type-detect-1.0.0.tgz#762217cc06db258ec48908a1298e8b95121e8ea2"
   integrity sha1-diIXzAbbJY7EiQihKY6LlRIejqI=
 
-typescript@~3.8.2:
-  version "3.8.2"
-  resolved "https://registry.yarnpkg.com/typescript/-/typescript-3.8.2.tgz#91d6868aaead7da74f493c553aeff76c0c0b1d5a"
-  integrity sha512-EgOVgL/4xfVrCMbhYKUQTdF37SQn4Iw73H5BgCrF1Abdun7Kwy/QZsE/ssAy0y4LxBbvua3PIbFsbRczWWnDdQ==
+typescript@~4.0.0-dev.20200722:
+  version "4.0.0-dev.20200722"
+  resolved "https://registry.yarnpkg.com/typescript/-/typescript-4.0.0-dev.20200722.tgz#b59dd5a3cd84a98d5aae0e4f3a3c58f0c81a3b9b"
+  integrity sha512-MmJ1YyPNK3JYeKLiTg5sQXdeZaMgt99Fg4BMRZhJmhoq1/x2V1cpXMYvE1rtIYl9K7NvmTDdU3WDW7ZOD6ybaw==
 
 uglify-js@^3.1.4:
   version "3.5.11"