diff --git a/src/java/org/apache/commons/lang/text/StrBuilder.java b/src/java/org/apache/commons/lang/text/StrBuilder.java
index 13281cefe..fd135fd11 100644
--- a/src/java/org/apache/commons/lang/text/StrBuilder.java
+++ b/src/java/org/apache/commons/lang/text/StrBuilder.java
@@ -1183,6 +1183,9 @@ public class StrBuilder implements Cloneable {
         if (width > 0) {
             ensureCapacity(size + width);
             String str = (obj == null ? getNullText() : obj.toString());
+            if (str == null) {
+                str = "";
+            }
             int strLen = str.length();
             if (strLen >= width) {
                 str.getChars(strLen - width, strLen, buffer, size);
@@ -1227,6 +1230,9 @@ public class StrBuilder implements Cloneable {
         if (width > 0) {
             ensureCapacity(size + width);
             String str = (obj == null ? getNullText() : obj.toString());
+            if (str == null) {
+                str = "";
+            }
             int strLen = str.length();
             if (strLen >= width) {
                 str.getChars(0, width, buffer, size);
diff --git a/src/test/org/apache/commons/lang/text/StrBuilderTest.java b/src/test/org/apache/commons/lang/text/StrBuilderTest.java
index 67e1ce1df..d58930805 100644
--- a/src/test/org/apache/commons/lang/text/StrBuilderTest.java
+++ b/src/test/org/apache/commons/lang/text/StrBuilderTest.java
@@ -1749,4 +1749,17 @@ public class StrBuilderTest extends TestCase {
         assertEquals( "The indexOf(char) method is looking beyond the end of the string", -1, sb.indexOf('h'));
     }
 
+    //-----------------------------------------------------------------------
+    public void testLang412Right() {
+        StrBuilder sb = new StrBuilder();
+        sb.appendFixedWidthPadRight(null, 10, '*');
+        assertEquals( "Failed to invoke appendFixedWidthPadRight correctly", "**********", sb.toString());
+    }
+
+    public void testLang412Left() {
+        StrBuilder sb = new StrBuilder();
+        sb.appendFixedWidthPadLeft(null, 10, '*');
+        assertEquals( "Failed to invoke appendFixedWidthPadLeft correctly", "**********", sb.toString());
+    }
+
 }