diff --git a/src/main/java/me/hatter/math/BinaryExponentiation.java b/src/main/java/me/hatter/math/BinaryExponentiation.java
index 9c0c690..62551da 100644
--- a/src/main/java/me/hatter/math/BinaryExponentiation.java
+++ b/src/main/java/me/hatter/math/BinaryExponentiation.java
@@ -21,14 +21,17 @@ public class BinaryExponentiation {
         }
     }
 
-    public static BigInteger binPow(BigInteger a, BigInteger b) {
+    public static BigInteger binPow(BigInteger base, BigInteger exponent) {
+        if (exponent.compareTo(BigInteger.ZERO) < 0) {
+            throw new ArithmeticException("Negative exponent");
+        }
         BigInteger result = BigInteger.ONE;
-        while (b.compareTo(BigInteger.ZERO) > 0) {
-            if (b.mod(BigInteger.valueOf(2)).compareTo(BigInteger.ONE) == 0) {
-                result = result.multiply(a);
+        while (exponent.compareTo(BigInteger.ZERO) > 0) {
+            if (exponent.mod(BigInteger.valueOf(2)).compareTo(BigInteger.ONE) == 0) {
+                result = result.multiply(base);
             }
-            a = a.multiply(a);
-            b = b.divide(BigInteger.valueOf(2));
+            base = base.multiply(base);
+            exponent = exponent.divide(BigInteger.valueOf(2));
         }
         return result;
     }