diff --git a/src/test/examplesJava9/backport/MathBackportJava9Main.java b/src/test/examplesJava9/backport/MathBackportJava9Main.java
index 5eefb65..c465af1 100644
--- a/src/test/examplesJava9/backport/MathBackportJava9Main.java
+++ b/src/test/examplesJava9/backport/MathBackportJava9Main.java
@@ -8,6 +8,7 @@
 
   public static void main(String[] args) {
     testMultiplyExactLongInt();
+    testMultiplyFull();
     testFloorDivLongInt();
     testFloorModLongInt();
   }
@@ -26,6 +27,16 @@
     }
   }
 
+  public static void testMultiplyFull() {
+    assertEquals(8L, Math.multiplyFull(2, 4));
+    assertEquals(4611686014132420609L,
+        Math.multiplyFull(Integer.MAX_VALUE, Integer.MAX_VALUE));
+    assertEquals(-4611686016279904256L,
+        Math.multiplyFull(Integer.MAX_VALUE, Integer.MIN_VALUE));
+    assertEquals(4611686018427387904L,
+        Math.multiplyFull(Integer.MIN_VALUE, Integer.MIN_VALUE));
+  }
+
   public static void testFloorDivLongInt() {
     assertEquals(1L, Math.floorDiv(4L, 4));
     assertEquals(1L, Math.floorDiv(-4L, -4));