diff --git a/packages/babylon/src/plugins/flow.js b/packages/babylon/src/plugins/flow.js
index 9a691cbff7..060f623649 100644
--- a/packages/babylon/src/plugins/flow.js
+++ b/packages/babylon/src/plugins/flow.js
@@ -671,7 +671,8 @@ export default function (instance) {
 
         if (canBeArrow && this.eat(tt.arrow)) {
           // ((lol): number => {});
-          let func = this.parseArrowExpression(this.startNodeAt(startLoc, startPos), [node]);
+          let params = node.type === "SequenceExpression" ? node.expressions : [node];
+          let func = this.parseArrowExpression(this.startNodeAt(startLoc, startPos), params);
           func.returnType = typeCastNode.typeAnnotation;
           return func;
         } else {
diff --git a/packages/babylon/test/fixtures/flow/type-annotations/99/actual.js b/packages/babylon/test/fixtures/flow/type-annotations/99/actual.js
new file mode 100644
index 0000000000..75ac9cb00c
--- /dev/null
+++ b/packages/babylon/test/fixtures/flow/type-annotations/99/actual.js
@@ -0,0 +1 @@
+(foo, bar): z => null
diff --git a/packages/babylon/test/fixtures/flow/type-annotations/99/expected.json b/packages/babylon/test/fixtures/flow/type-annotations/99/expected.json
new file mode 100644
index 0000000000..b261c3eff9
--- /dev/null
+++ b/packages/babylon/test/fixtures/flow/type-annotations/99/expected.json
@@ -0,0 +1,429 @@
+{
+  "type": "File",
+  "start": 0,
+  "end": 21,
+  "loc": {
+    "start": {
+      "line": 1,
+      "column": 0
+    },
+    "end": {
+      "line": 1,
+      "column": 21
+    }
+  },
+  "program": {
+    "type": "Program",
+    "start": 0,
+    "end": 21,
+    "loc": {
+      "start": {
+        "line": 1,
+        "column": 0
+      },
+      "end": {
+        "line": 1,
+        "column": 21
+      }
+    },
+    "sourceType": "module",
+    "body": [
+      {
+        "type": "ExpressionStatement",
+        "start": 0,
+        "end": 21,
+        "loc": {
+          "start": {
+            "line": 1,
+            "column": 0
+          },
+          "end": {
+            "line": 1,
+            "column": 21
+          }
+        },
+        "expression": {
+          "type": "ArrowFunctionExpression",
+          "start": 0,
+          "end": 21,
+          "loc": {
+            "start": {
+              "line": 1,
+              "column": 0
+            },
+            "end": {
+              "line": 1,
+              "column": 21
+            }
+          },
+          "id": null,
+          "generator": false,
+          "expression": true,
+          "async": false,
+          "params": [
+            {
+              "type": "Identifier",
+              "start": 1,
+              "end": 4,
+              "loc": {
+                "start": {
+                  "line": 1,
+                  "column": 1
+                },
+                "end": {
+                  "line": 1,
+                  "column": 4
+                }
+              },
+              "name": "foo"
+            },
+            {
+              "type": "Identifier",
+              "start": 6,
+              "end": 9,
+              "loc": {
+                "start": {
+                  "line": 1,
+                  "column": 6
+                },
+                "end": {
+                  "line": 1,
+                  "column": 9
+                }
+              },
+              "name": "bar"
+            }
+          ],
+          "body": {
+            "type": "NullLiteral",
+            "start": 17,
+            "end": 21,
+            "loc": {
+              "start": {
+                "line": 1,
+                "column": 17
+              },
+              "end": {
+                "line": 1,
+                "column": 21
+              }
+            }
+          },
+          "returnType": {
+            "type": "TypeAnnotation",
+            "start": 10,
+            "end": 13,
+            "loc": {
+              "start": {
+                "line": 1,
+                "column": 10
+              },
+              "end": {
+                "line": 1,
+                "column": 13
+              }
+            },
+            "typeAnnotation": {
+              "type": "GenericTypeAnnotation",
+              "start": 12,
+              "end": 13,
+              "loc": {
+                "start": {
+                  "line": 1,
+                  "column": 12
+                },
+                "end": {
+                  "line": 1,
+                  "column": 13
+                }
+              },
+              "typeParameters": null,
+              "id": {
+                "type": "Identifier",
+                "start": 12,
+                "end": 13,
+                "loc": {
+                  "start": {
+                    "line": 1,
+                    "column": 12
+                  },
+                  "end": {
+                    "line": 1,
+                    "column": 13
+                  }
+                },
+                "name": "z"
+              }
+            }
+          }
+        }
+      }
+    ],
+    "directives": []
+  },
+  "comments": [],
+  "tokens": [
+    {
+      "type": {
+        "label": "(",
+        "beforeExpr": true,
+        "startsExpr": true,
+        "rightAssociative": false,
+        "isLoop": false,
+        "isAssign": false,
+        "prefix": false,
+        "postfix": false,
+        "binop": null
+      },
+      "start": 0,
+      "end": 1,
+      "loc": {
+        "start": {
+          "line": 1,
+          "column": 0
+        },
+        "end": {
+          "line": 1,
+          "column": 1
+        }
+      }
+    },
+    {
+      "type": {
+        "label": "name",
+        "beforeExpr": false,
+        "startsExpr": true,
+        "rightAssociative": false,
+        "isLoop": false,
+        "isAssign": false,
+        "prefix": false,
+        "postfix": false,
+        "binop": null
+      },
+      "value": "foo",
+      "start": 1,
+      "end": 4,
+      "loc": {
+        "start": {
+          "line": 1,
+          "column": 1
+        },
+        "end": {
+          "line": 1,
+          "column": 4
+        }
+      }
+    },
+    {
+      "type": {
+        "label": ",",
+        "beforeExpr": true,
+        "startsExpr": false,
+        "rightAssociative": false,
+        "isLoop": false,
+        "isAssign": false,
+        "prefix": false,
+        "postfix": false,
+        "binop": null,
+        "updateContext": null
+      },
+      "start": 4,
+      "end": 5,
+      "loc": {
+        "start": {
+          "line": 1,
+          "column": 4
+        },
+        "end": {
+          "line": 1,
+          "column": 5
+        }
+      }
+    },
+    {
+      "type": {
+        "label": "name",
+        "beforeExpr": false,
+        "startsExpr": true,
+        "rightAssociative": false,
+        "isLoop": false,
+        "isAssign": false,
+        "prefix": false,
+        "postfix": false,
+        "binop": null
+      },
+      "value": "bar",
+      "start": 6,
+      "end": 9,
+      "loc": {
+        "start": {
+          "line": 1,
+          "column": 6
+        },
+        "end": {
+          "line": 1,
+          "column": 9
+        }
+      }
+    },
+    {
+      "type": {
+        "label": ")",
+        "beforeExpr": false,
+        "startsExpr": false,
+        "rightAssociative": false,
+        "isLoop": false,
+        "isAssign": false,
+        "prefix": false,
+        "postfix": false,
+        "binop": null
+      },
+      "start": 9,
+      "end": 10,
+      "loc": {
+        "start": {
+          "line": 1,
+          "column": 9
+        },
+        "end": {
+          "line": 1,
+          "column": 10
+        }
+      }
+    },
+    {
+      "type": {
+        "label": ":",
+        "beforeExpr": true,
+        "startsExpr": false,
+        "rightAssociative": false,
+        "isLoop": false,
+        "isAssign": false,
+        "prefix": false,
+        "postfix": false,
+        "binop": null,
+        "updateContext": null
+      },
+      "start": 10,
+      "end": 11,
+      "loc": {
+        "start": {
+          "line": 1,
+          "column": 10
+        },
+        "end": {
+          "line": 1,
+          "column": 11
+        }
+      }
+    },
+    {
+      "type": {
+        "label": "name",
+        "beforeExpr": false,
+        "startsExpr": true,
+        "rightAssociative": false,
+        "isLoop": false,
+        "isAssign": false,
+        "prefix": false,
+        "postfix": false,
+        "binop": null
+      },
+      "value": "z",
+      "start": 12,
+      "end": 13,
+      "loc": {
+        "start": {
+          "line": 1,
+          "column": 12
+        },
+        "end": {
+          "line": 1,
+          "column": 13
+        }
+      }
+    },
+    {
+      "type": {
+        "label": "=>",
+        "beforeExpr": true,
+        "startsExpr": false,
+        "rightAssociative": false,
+        "isLoop": false,
+        "isAssign": false,
+        "prefix": false,
+        "postfix": false,
+        "binop": null,
+        "updateContext": null
+      },
+      "start": 14,
+      "end": 16,
+      "loc": {
+        "start": {
+          "line": 1,
+          "column": 14
+
+
+        },
+        "end": {
+          "line": 1,
+          "column": 16
+        }
+      }
+    },
+    {
+      "type": {
+        "label": "null",
+        "keyword": "null",
+        "beforeExpr": false,
+        "startsExpr": true,
+        "rightAssociative": false,
+        "isLoop": false,
+        "isAssign": false,
+        "prefix": false,
+        "postfix": false,
+        "binop": null,
+        "updateContext": null
+      },
+      "value": "null",
+      "start": 17,
+      "end": 21,
+      "loc": {
+        "start": {
+          "line": 1,
+          "column": 17
+        },
+        "end": {
+          "line": 1,
+          "column": 21
+        }
+      }
+    },
+    {
+      "type": {
+        "label": "eof",
+        "beforeExpr": false,
+        "startsExpr": false,
+        "rightAssociative": false,
+        "isLoop": false,
+        "isAssign": false,
+        "prefix": false,
+        "postfix": false,
+        "binop": null,
+        "updateContext": null
+      },
+      "start": 21,
+      "end": 21,
+      "loc": {
+        "start": {
+          "line": 1,
+          "column": 21
+        },
+        "end": {
+          "line": 1,
+          "column": 21
+        }
+      }
+    }
+  ]
+}