diff --git a/src/java/org/apache/commons/lang/builder/EqualsBuilder.java b/src/java/org/apache/commons/lang/builder/EqualsBuilder.java
index 6901c8e5c..a1648aa11 100644
--- a/src/java/org/apache/commons/lang/builder/EqualsBuilder.java
+++ b/src/java/org/apache/commons/lang/builder/EqualsBuilder.java
@@ -377,8 +377,8 @@ public class EqualsBuilder {
         }
         Class lhsClass = lhs.getClass();
         if (!lhsClass.isArray()) {
-            if (lhs instanceof java.math.BigDecimal) {
-                isEquals = (((java.math.BigDecimal)lhs).compareTo(rhs) == 0);
+            if (lhs instanceof java.math.BigDecimal && rhs instanceof java.math.BigDecimal) {
+                isEquals = (((java.math.BigDecimal)lhs).compareTo((java.math.BigDecimal)rhs) == 0);
             } else {
                 // The simple case, not an array, just test the element
                 isEquals = lhs.equals(rhs);