diff --git a/src/main/java/helpers/ScryptHelper.java b/src/main/java/helpers/ScryptHelper.java
index bf4c903..0503a26 100644
--- a/src/main/java/helpers/ScryptHelper.java
+++ b/src/main/java/helpers/ScryptHelper.java
@@ -15,7 +15,8 @@
 /**
  * Wrapper for Bouncy Castle's scrypt implementation.
  *
- * Generates salted scrypt hashes in a format similar to Modular Crypt Format (MCF).
+ * Generates salted scrypt hashes in a format similar to Modular Crypt Format
+ * (MCF).
  *
  * @author Mark George <mark.george@otago.ac.nz>
  */
@@ -73,8 +74,7 @@
 	}
 
 	/**
-	 * Checks a hash (as generated by the hash method) against a
-	 * password.
+	 * Checks a hash (as generated by the hash method) against a password.
 	 *
 	 * @param mcfHash The MCF formatted hash.
 	 * @param password The password.
@@ -130,14 +130,12 @@
 	}
 
 	private static int log2(int operand) {
-		int result = 0;
-
-		do {
-			operand = operand >> 1;
-			result++;
-		} while (operand > 1);
-
-		return result;
+		double log2 = Math.log(operand) / Math.log(2);
+		if (log2 % 1 != 0) {
+			throw new IllegalArgumentException("N must be a power of 2.");
+		} else {
+			return Math.toIntExact(Math.round(log2));
+		}
 	}
 
 	/*