diff --git a/src/math/big/example_test.go b/src/math/big/example_test.go
index cfc7735..31ca784 100644
--- a/src/math/big/example_test.go
+++ b/src/math/big/example_test.go
@@ -25,6 +25,13 @@
 	// Output: 420
 }
 
+func ExampleFloat_SetString() {
+	f := new(big.Float)
+	f.SetString("3.14159")
+	fmt.Println(f)
+	// Output: 3.14159
+}
+
 func ExampleRat_Scan() {
 	// The Scan function is rarely used directly;
 	// the fmt package recognizes it as an implementation of fmt.Scanner.