diff --git a/packages/babel-generator/src/buffer.js b/packages/babel-generator/src/buffer.js
index ed294897c0..a1390c1762 100644
--- a/packages/babel-generator/src/buffer.js
+++ b/packages/babel-generator/src/buffer.js
@@ -97,10 +97,23 @@ export default class Buffer {
     if (this._queue.length > 0 && this._queue[0][0] === ";") this._queue.shift();
   }
 
-  endsWith(str: string): boolean {
+  endsWith(suffix: string): boolean {
+    // Fast path to avoid iterating over this._queue.
+    if (suffix.length === 1) {
+      let last;
+      if (this._queue.length > 0) {
+        const str = this._queue[0][0];
+        last = str[str.length - 1];
+      } else {
+        last = this._last;
+      }
+
+      return last === suffix;
+    }
+
     const end = this._last + this._queue.reduce((acc, item) => item[0] + acc, "");
-    if (str.length <= end.length) {
-      return end.slice(-str.length) === str;
+    if (suffix.length <= end.length) {
+      return end.slice(-suffix.length) === suffix;
     }
 
     // We assume that everything being matched is at most a single token plus some whitespace,
@@ -108,15 +121,6 @@ export default class Buffer {
     return false;
   }
 
-  getLast(): string {
-    if (this._queue.length > 0) {
-      const last = this._queue[0][0];
-      return last[last.length - 1];
-    }
-
-    return this._last;
-  }
-
   hasContent(): boolean {
     return this._queue.length > 0 || !!this._last;
   }
diff --git a/packages/babel-generator/src/printer.js b/packages/babel-generator/src/printer.js
index f0f791871a..ad3884e617 100644
--- a/packages/babel-generator/src/printer.js
+++ b/packages/babel-generator/src/printer.js
@@ -131,14 +131,13 @@ export default class Printer {
    */
 
   token(str: string): void {
-    const last = this._buf.getLast();
     // space is mandatory to avoid outputting <!--
     // http://javascript.spec.whatwg.org/#comment-syntax
-    if ((str === "--" && last === "!") ||
+    if ((str === "--" && this.endsWith("!")) ||
 
       // Need spaces for operators of the same kind to avoid: `a+++b`
-      (str[0] === "+" && last === "+") ||
-      (str[0] === "-" && last === "-")) {
+      (str[0] === "+" && this.endsWith("+")) ||
+      (str[0] === "-" && this.endsWith("-"))) {
       this._space();
     }