diff --git a/src/fast-path.js b/src/fast-path.js
index ea18f8284dfd..8bbc490fe12c 100644
--- a/src/fast-path.js
+++ b/src/fast-path.js
@@ -424,6 +424,8 @@ FPp.needsParens = function(assumeExpressionContext) {
         return false;
       } else if (parent.type === "ExpressionStatement") {
         return node.left.type === "ObjectPattern";
+      } else if (parent.type === "AssignmentExpression") {
+        return false;
       }
       return true;
 
diff --git a/tests/assignment_expression/__snapshots__/jsfmt.spec.js.snap b/tests/assignment_expression/__snapshots__/jsfmt.spec.js.snap
new file mode 100644
index 000000000000..cc53cafe36d0
--- /dev/null
+++ b/tests/assignment_expression/__snapshots__/jsfmt.spec.js.snap
@@ -0,0 +1,8 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`assignment_expression.js 1`] = `
+"this.size = this._origin = this._capacity = 0;
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+this.size = this._origin = this._capacity = 0;
+"
+`;
diff --git a/tests/assignment_expression/assignment_expression.js b/tests/assignment_expression/assignment_expression.js
new file mode 100644
index 000000000000..0f0acca28399
--- /dev/null
+++ b/tests/assignment_expression/assignment_expression.js
@@ -0,0 +1 @@
+this.size = this._origin = this._capacity = 0;
diff --git a/tests/assignment_expression/jsfmt.spec.js b/tests/assignment_expression/jsfmt.spec.js
new file mode 100644
index 000000000000..989047bccc52
--- /dev/null
+++ b/tests/assignment_expression/jsfmt.spec.js
@@ -0,0 +1 @@
+run_spec(__dirname);