diff --git a/hbase-server/src/main/java/org/apache/hadoop/hbase/client/HTable.java b/hbase-server/src/main/java/org/apache/hadoop/hbase/client/HTable.java
index 377988d74c7..b7b15065b33 100644
--- a/hbase-server/src/main/java/org/apache/hadoop/hbase/client/HTable.java
+++ b/hbase-server/src/main/java/org/apache/hadoop/hbase/client/HTable.java
@@ -921,7 +921,9 @@ public class HTable implements HTableInterface {
     if (row == null) {
       npe = new NullPointerException("row is null");
     } else if (family == null) {
-      npe = new NullPointerException("column is null");
+      npe = new NullPointerException("family is null");
+    } else if (qualifier == null) {
+      npe = new NullPointerException("qualifier is null");
     }
     if (npe != null) {
       throw new IOException(
diff --git a/hbase-server/src/main/java/org/apache/hadoop/hbase/client/Increment.java b/hbase-server/src/main/java/org/apache/hadoop/hbase/client/Increment.java
index 0a8033c0302..a21bd48e4a7 100644
--- a/hbase-server/src/main/java/org/apache/hadoop/hbase/client/Increment.java
+++ b/hbase-server/src/main/java/org/apache/hadoop/hbase/client/Increment.java
@@ -78,6 +78,9 @@ public class Increment implements Row {
    * @param rowLock previously acquired row lock, or null
    */
   public Increment(byte [] row, RowLock rowLock) {
+    if (row == null) {
+      throw new IllegalArgumentException("Cannot increment a null row");
+    }
     this.row = row;
     if(rowLock != null) {
       this.lockId = rowLock.getLockId();
@@ -95,6 +98,12 @@ public class Increment implements Row {
    * @return the Increment object
    */
   public Increment addColumn(byte [] family, byte [] qualifier, long amount) {
+    if (family == null) {
+      throw new IllegalArgumentException("family cannot be null");
+    }
+    if (qualifier == null) {
+      throw new IllegalArgumentException("qualifier cannot be null");
+    }
     NavigableMap<byte [], Long> set = familyMap.get(family);
     if(set == null) {
       set = new TreeMap<byte [], Long>(Bytes.BYTES_COMPARATOR);
diff --git a/hbase-server/src/main/ruby/hbase/table.rb b/hbase-server/src/main/ruby/hbase/table.rb
index a4d1fe94506..bcbb3ae69a0 100644
--- a/hbase-server/src/main/ruby/hbase/table.rb
+++ b/hbase-server/src/main/ruby/hbase/table.rb
@@ -154,6 +154,9 @@ EOF
     def _incr_internal(row, column, value = nil)
       value ||= 1
       family, qualifier = parse_column_name(column)
+      if qualifier.nil?
+	  raise ArgumentError, "Failed to provide both column family and column qualifier for incr"
+      end
       @table.incrementColumnValue(row.to_s.to_java_bytes, family, qualifier, value)
     end
 
diff --git a/hbase-server/src/test/java/org/apache/hadoop/hbase/client/TestFromClientSide.java b/hbase-server/src/test/java/org/apache/hadoop/hbase/client/TestFromClientSide.java
index 2f688efd717..23852121d2e 100644
--- a/hbase-server/src/test/java/org/apache/hadoop/hbase/client/TestFromClientSide.java
+++ b/hbase-server/src/test/java/org/apache/hadoop/hbase/client/TestFromClientSide.java
@@ -4295,6 +4295,59 @@ public class TestFromClientSide {
     }
   }
 
+  @Test
+  public void testIncrementInvalidArguments() throws Exception {
+    LOG.info("Starting testIncrementInvalidArguments");
+    final byte[] TABLENAME = Bytes.toBytes("testIncrementInvalidArguments");
+    HTable ht = TEST_UTIL.createTable(TABLENAME, FAMILY);
+    final byte[] COLUMN = Bytes.toBytes("column");
+    try {
+      // try null row
+      ht.incrementColumnValue(null, FAMILY, COLUMN, 5);
+      fail("Should have thrown IOException");
+    } catch (IOException iox) {
+      // success
+    }
+    try {
+      // try null family
+      ht.incrementColumnValue(ROW, null, COLUMN, 5);
+      fail("Should have thrown IOException");
+    } catch (IOException iox) {
+      // success
+    }
+    try {
+      // try null qualifier
+      ht.incrementColumnValue(ROW, FAMILY, null, 5);
+      fail("Should have thrown IOException");
+    } catch (IOException iox) {
+      // success
+    }
+    // try null row
+    try {
+      Increment incNoRow = new Increment(null);
+      incNoRow.addColumn(FAMILY, COLUMN, 5);
+      fail("Should have thrown IllegalArgumentException");
+    } catch (IllegalArgumentException iax) {
+      // success
+    }
+    // try null family
+    try {
+      Increment incNoFamily = new Increment(ROW);
+      incNoFamily.addColumn(null, COLUMN, 5);
+      fail("Should have thrown IllegalArgumentException");
+    } catch (IllegalArgumentException iax) {
+      // success
+    }
+    // try null qualifier
+    try {
+      Increment incNoQualifier = new Increment(ROW);
+      incNoQualifier.addColumn(FAMILY, null, 5);
+      fail("Should have thrown IllegalArgumentException");
+    } catch (IllegalArgumentException iax) {
+      // success
+    }
+  }
+
 
 
   @Test