diff --git a/lib/output.js b/lib/output.js
index 7fe61af3..4a307bf8 100644
--- a/lib/output.js
+++ b/lib/output.js
@@ -1109,7 +1109,7 @@ function OutputStream(options) {
     });
     DEFPRINT(AST_Hole, noop);
     DEFPRINT(AST_Infinity, function(self, output){
-        output.print("1/0");
+        output.print("(1/0)");
     });
     DEFPRINT(AST_NaN, function(self, output){
         output.print("0/0");
diff --git a/test/compress/issue-597.js b/test/compress/issue-597.js
new file mode 100644
index 00000000..a9efdfed
--- /dev/null
+++ b/test/compress/issue-597.js
@@ -0,0 +1,4 @@
+infinity_to_string: {
+    input: { Infinity.toString() }
+    expect: { (1/0).toString() }
+}