diff --git a/types/structured-source/index.d.ts b/types/structured-source/index.d.ts
new file mode 100644
index 0000000000..ce7325cf9d
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+++ b/types/structured-source/index.d.ts
@@ -0,0 +1,29 @@
+// Type definitions for structured-source 3.0
+// Project: https://github.com/Constellation/structured-source
+// Definitions by: azu <https://github.com/azu>
+// Definitions: https://github.com/DefinitelyTyped/DefinitelyTyped
+
+declare namespace StructuredSource {
+    interface SourcePosition {
+        // Line number starts with 1.
+        line: number;
+        // Column number starts with 0.
+        column: number;
+    }
+    interface SourceLocation {
+        start: SourcePosition;
+        end: SourcePosition;
+    }
+}
+
+declare class StructuredSource {
+    /**
+     * @param source - source code text.
+     */
+    constructor(source: string);
+    locationToRange(loc: StructuredSource.SourceLocation): [number, number];
+    rangeToLocation(range: [number, number]): StructuredSource.SourceLocation;
+    positionToIndex(pos: StructuredSource.SourcePosition): number;
+    indexToPosition(index: number): StructuredSource.SourcePosition;
+}
+export = StructuredSource;
diff --git a/types/structured-source/structured-source-tests.ts b/types/structured-source/structured-source-tests.ts
new file mode 100644
index 0000000000..cda6e99af2
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+++ b/types/structured-source/structured-source-tests.ts
@@ -0,0 +1,15 @@
+import StructuredSource = require('structured-source');
+
+const src = new StructuredSource('aaa\u2028aaaa\u2029aaaaa\n');
+
+// $ExpectType: number
+src.positionToIndex({ line: 1, column: 2 });
+// $ExpectType: { line: number, column: number }
+src.indexToPosition(2);
+// $ExpectType: { start: { line: number, column: number}, end: { line: number, column: number } }
+src.rangeToLocation([0, 2]);
+// $ExpectType: [ number, number ]
+src.locationToRange({
+    start: { line: 1, column: 0 },
+    end: { line: 1, column: 2 }
+});
diff --git a/types/structured-source/tsconfig.json b/types/structured-source/tsconfig.json
new file mode 100644
index 0000000000..f0d949503e
--- /dev/null
+++ b/types/structured-source/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",
+        "structured-source-tests.ts"
+    ]
+}
diff --git a/types/structured-source/tslint.json b/types/structured-source/tslint.json
new file mode 100644
index 0000000000..3db14f85ea
--- /dev/null
+++ b/types/structured-source/tslint.json
@@ -0,0 +1 @@
+{ "extends": "dtslint/dt.json" }