diff --git a/lib/ast-converter.js b/lib/ast-converter.js
index 72f8caa..b63aa32 100644
--- a/lib/ast-converter.js
+++ b/lib/ast-converter.js
@@ -765,22 +765,36 @@ module.exports = function(ast, extra) {
             // Declarations
 
             case SyntaxKind.FunctionDeclaration:
+
+                var functionDeclarationType = "FunctionDeclaration";
+                if (node.modifiers && node.modifiers.length) {
+                    var isDeclareFunction = node.modifiers.some(function(modifier) {
+                        return modifier.kind === ts.SyntaxKind.DeclareKeyword;
+                    });
+                    if (isDeclareFunction) {
+                        functionDeclarationType = "DeclareFunction";
+                    }
+                }
+
                 assign(result, {
-                    type: "FunctionDeclaration",
+                    type: functionDeclarationType,
                     id: convertChild(node.name),
                     generator: !!node.asteriskToken,
                     expression: false,
                     params: node.parameters.map(convertChild),
                     body: convertChild(node.body)
                 });
+
                 // Process returnType
                 if (node.type) {
                     result.returnType = convertTypeAnnotation(node.type);
                 }
+
                 // Process typeParameters
                 if (node.typeParameters && node.typeParameters.length) {
                     result.typeParameters = convertTSTypeParametersToTypeParametersDeclaration(node.typeParameters);
                 }
+
                 // check for exports
                 result = fixExports(node, result, ast);
 
diff --git a/tests/fixtures/typescript/basics/declare-function.result.js b/tests/fixtures/typescript/basics/declare-function.result.js
new file mode 100644
index 0000000..8531c5b
--- /dev/null
+++ b/tests/fixtures/typescript/basics/declare-function.result.js
@@ -0,0 +1,313 @@
+module.exports = {
+    "type": "Program",
+    "range": [
+        0,
+        42
+    ],
+    "loc": {
+        "start": {
+            "line": 1,
+            "column": 0
+        },
+        "end": {
+            "line": 1,
+            "column": 42
+        }
+    },
+    "body": [
+        {
+            "type": "DeclareFunction",
+            "range": [
+                0,
+                42
+            ],
+            "loc": {
+                "start": {
+                    "line": 1,
+                    "column": 0
+                },
+                "end": {
+                    "line": 1,
+                    "column": 42
+                }
+            },
+            "id": {
+                "type": "Identifier",
+                "range": [
+                    17,
+                    20
+                ],
+                "loc": {
+                    "start": {
+                        "line": 1,
+                        "column": 17
+                    },
+                    "end": {
+                        "line": 1,
+                        "column": 20
+                    }
+                },
+                "name": "foo"
+            },
+            "generator": false,
+            "expression": false,
+            "params": [
+                {
+                    "type": "Identifier",
+                    "range": [
+                        21,
+                        24
+                    ],
+                    "loc": {
+                        "start": {
+                            "line": 1,
+                            "column": 21
+                        },
+                        "end": {
+                            "line": 1,
+                            "column": 24
+                        }
+                    },
+                    "name": "bar"
+                }
+            ],
+            "body": null,
+            "returnType": {
+                "type": "TypeAnnotation",
+                "loc": {
+                    "start": {
+                        "line": 1,
+                        "column": 35
+                    },
+                    "end": {
+                        "line": 1,
+                        "column": 41
+                    }
+                },
+                "range": [
+                    35,
+                    41
+                ],
+                "typeAnnotation": {
+                    "type": "TSStringKeyword",
+                    "range": [
+                        35,
+                        41
+                    ],
+                    "loc": {
+                        "start": {
+                            "line": 1,
+                            "column": 35
+                        },
+                        "end": {
+                            "line": 1,
+                            "column": 41
+                        }
+                    },
+                    "flags": 0
+                }
+            }
+        }
+    ],
+    "sourceType": "script",
+    "tokens": [
+        {
+            "type": "Identifier",
+            "value": "declare",
+            "range": [
+                0,
+                7
+            ],
+            "loc": {
+                "start": {
+                    "line": 1,
+                    "column": 0
+                },
+                "end": {
+                    "line": 1,
+                    "column": 7
+                }
+            }
+        },
+        {
+            "type": "Keyword",
+            "value": "function",
+            "range": [
+                8,
+                16
+            ],
+            "loc": {
+                "start": {
+                    "line": 1,
+                    "column": 8
+                },
+                "end": {
+                    "line": 1,
+                    "column": 16
+                }
+            }
+        },
+        {
+            "type": "Identifier",
+            "value": "foo",
+            "range": [
+                17,
+                20
+            ],
+            "loc": {
+                "start": {
+                    "line": 1,
+                    "column": 17
+                },
+                "end": {
+                    "line": 1,
+                    "column": 20
+                }
+            }
+        },
+        {
+            "type": "Punctuator",
+            "value": "(",
+            "range": [
+                20,
+                21
+            ],
+            "loc": {
+                "start": {
+                    "line": 1,
+                    "column": 20
+                },
+                "end": {
+                    "line": 1,
+                    "column": 21
+                }
+            }
+        },
+        {
+            "type": "Identifier",
+            "value": "bar",
+            "range": [
+                21,
+                24
+            ],
+            "loc": {
+                "start": {
+                    "line": 1,
+                    "column": 21
+                },
+                "end": {
+                    "line": 1,
+                    "column": 24
+                }
+            }
+        },
+        {
+            "type": "Punctuator",
+            "value": ":",
+            "range": [
+                24,
+                25
+            ],
+            "loc": {
+                "start": {
+                    "line": 1,
+                    "column": 24
+                },
+                "end": {
+                    "line": 1,
+                    "column": 25
+                }
+            }
+        },
+        {
+            "type": "Identifier",
+            "value": "string",
+            "range": [
+                26,
+                32
+            ],
+            "loc": {
+                "start": {
+                    "line": 1,
+                    "column": 26
+                },
+                "end": {
+                    "line": 1,
+                    "column": 32
+                }
+            }
+        },
+        {
+            "type": "Punctuator",
+            "value": ")",
+            "range": [
+                32,
+                33
+            ],
+            "loc": {
+                "start": {
+                    "line": 1,
+                    "column": 32
+                },
+                "end": {
+                    "line": 1,
+                    "column": 33
+                }
+            }
+        },
+        {
+            "type": "Punctuator",
+            "value": ":",
+            "range": [
+                33,
+                34
+            ],
+            "loc": {
+                "start": {
+                    "line": 1,
+                    "column": 33
+                },
+                "end": {
+                    "line": 1,
+                    "column": 34
+                }
+            }
+        },
+        {
+            "type": "Identifier",
+            "value": "string",
+            "range": [
+                35,
+                41
+            ],
+            "loc": {
+                "start": {
+                    "line": 1,
+                    "column": 35
+                },
+                "end": {
+                    "line": 1,
+                    "column": 41
+                }
+            }
+        },
+        {
+            "type": "Punctuator",
+            "value": ";",
+            "range": [
+                41,
+                42
+            ],
+            "loc": {
+                "start": {
+                    "line": 1,
+                    "column": 41
+                },
+                "end": {
+                    "line": 1,
+                    "column": 42
+                }
+            }
+        }
+    ]
+};
diff --git a/tests/fixtures/typescript/basics/declare-function.src.ts b/tests/fixtures/typescript/basics/declare-function.src.ts
new file mode 100644
index 0000000..4f4d107
--- /dev/null
+++ b/tests/fixtures/typescript/basics/declare-function.src.ts
@@ -0,0 +1 @@
+declare function foo(bar: string): string;
\ No newline at end of file