diff --git a/types/topo/index.d.ts b/types/topo/index.d.ts
new file mode 100644
index 0000000000..92c8f2153e
--- /dev/null
+++ b/types/topo/index.d.ts
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+// Type definitions for topo 3.0
+// Project: https://github.com/hapijs/topo#readme
+// Definitions by: BendingBender <https://github.com/BendingBender>
+// Definitions: https://github.com/DefinitelyTyped/DefinitelyTyped
+// TypeScript Version: 2.3
+
+export = Topo;
+
+/**
+ * The Topo object is the container for topologically sorting a list of nodes with non-circular interdependencies.
+ */
+declare class Topo<TNode = any, TGroup = string> {
+    /**
+     * An array of the topologically sorted nodes. This list is renewed upon each call to `topo.add()`.
+     */
+    nodes: TNode[];
+
+    /**
+     * Specifies an additional node or list of nodes to be topologically sorted.
+     *
+     * @param nodes a mixed value or array of mixed values to be added as nodes to the topologically sorted list.
+     * @param options optional sorting information about the `nodes`:
+     * - `group` - a string naming the group to which `nodes` should be assigned. The group name `'?'` is reserved.
+     * - `before` - a string or array of strings specifying the groups that `nodes` must precede in the topological sort.
+     * - `after` - a string or array of strings specifying the groups that `nodes` must succeed in the topological sort.
+     * - `sort` - a numerical value used to sort items when performing a `topo.merge()`.
+     * @returns an array of the topologically sorted nodes.
+     */
+    add(
+        nodes: TNode | TNode[],
+        options?: {
+            group?: TGroup;
+            before?: TGroup | TGroup[];
+            after?: TGroup | TGroup[];
+            sort?: number;
+        }
+    ): TNode[];
+
+    /**
+     * Merges another `Topo` object into the current object.
+     * If the order in which items have been added to each list matters, use the `sort` option in `topo.add()`
+     * with an incrementing value providing an absolute sort order among all items added to either object.
+     *
+     * @param others the other object or array of objects to be merged into the current one. `null` values are ignored.
+     * @returns an array of the topologically sorted nodes. Will throw if a dependency error is found as a result of the combined items.
+     */
+    merge(others: Topo<TNode, TGroup> | Array<Topo<TNode, TGroup>>): TNode[];
+}
diff --git a/types/topo/topo-tests.ts b/types/topo/topo-tests.ts
new file mode 100644
index 0000000000..d880f15e80
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+++ b/types/topo/topo-tests.ts
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+import Topo = require('topo');
+
+const morning = new Topo<string, 'breakfast' | 'prep' | 'dinner'>();
+
+morning.add('Nap', { after: ['breakfast', 'prep'] }); // $ExpectType string[]
+morning.add('Nap', { after: 'foo' }); // $ExpectError
+morning.add(['Make toast', 'Pour juice'], { before: 'breakfast', group: 'prep' }); // $ExpectType string[]
+morning.add('Eat breakfast', { group: 'breakfast' }); // $ExpectType string[]
+
+morning.nodes; // $ExpectType string[]
+
+const dinner = new Topo<string, 'breakfast' | 'prep' | 'dinner'>();
+dinner.add('Eat dinner', { group: 'dinner', after: 'breakfast' }); // $ExpectType string[]
+
+morning.merge(dinner);
diff --git a/types/topo/tsconfig.json b/types/topo/tsconfig.json
new file mode 100644
index 0000000000..8ebfca72df
--- /dev/null
+++ b/types/topo/tsconfig.json
@@ -0,0 +1,23 @@
+{
+    "compilerOptions": {
+        "module": "commonjs",
+        "lib": [
+            "es6"
+        ],
+        "noImplicitAny": true,
+        "noImplicitThis": true,
+        "strictNullChecks": true,
+        "strictFunctionTypes": true,
+        "baseUrl": "../",
+        "typeRoots": [
+            "../"
+        ],
+        "types": [],
+        "noEmit": true,
+        "forceConsistentCasingInFileNames": true
+    },
+    "files": [
+        "index.d.ts",
+        "topo-tests.ts"
+    ]
+}
diff --git a/types/topo/tslint.json b/types/topo/tslint.json
new file mode 100644
index 0000000000..3db14f85ea
--- /dev/null
+++ b/types/topo/tslint.json
@@ -0,0 +1 @@
+{ "extends": "dtslint/dt.json" }