diff --git a/src/main/java/com/android/tools/r8/ir/code/ConstNumber.java b/src/main/java/com/android/tools/r8/ir/code/ConstNumber.java
index dc66e3c..d6da301 100644
--- a/src/main/java/com/android/tools/r8/ir/code/ConstNumber.java
+++ b/src/main/java/com/android/tools/r8/ir/code/ConstNumber.java
@@ -46,7 +46,10 @@
   }
 
   public static ConstNumber asConstNumberOrNull(Instruction instruction) {
-    return (ConstNumber) instruction;
+    if (instruction == null) {
+      return null;
+    }
+    return instruction.asConstNumber();
   }
 
   @Override