diff --git a/core/src/main/java/org/jclouds/domain/LoginCredentials.java b/core/src/main/java/org/jclouds/domain/LoginCredentials.java
index c22f013e99..68866b955c 100644
--- a/core/src/main/java/org/jclouds/domain/LoginCredentials.java
+++ b/core/src/main/java/org/jclouds/domain/LoginCredentials.java
@@ -64,6 +64,8 @@ public class LoginCredentials extends Credentials {
 
       public Builder password(String password) {
          this.password = Optional.fromNullable(password);
+         if (privateKey == null)
+            noPrivateKey();
          return this;
       }
 
@@ -74,6 +76,8 @@ public class LoginCredentials extends Credentials {
 
       public Builder privateKey(String privateKey) {
          this.privateKey = Optional.fromNullable(privateKey);
+         if (password == null)
+            noPassword();
          return this;
       }
 
diff --git a/core/src/test/java/org/jclouds/domain/LoginCredentialsTest.java b/core/src/test/java/org/jclouds/domain/LoginCredentialsTest.java
new file mode 100644
index 0000000000..b22e7a4b2a
--- /dev/null
+++ b/core/src/test/java/org/jclouds/domain/LoginCredentialsTest.java
@@ -0,0 +1,56 @@
+/**
+ * Licensed to jclouds, Inc. (jclouds) under one or more
+ * contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  jclouds licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+package org.jclouds.domain;
+
+import static org.testng.Assert.assertEquals;
+
+import org.testng.annotations.Test;
+
+import com.google.common.base.Optional;
+
+/**
+ * @author Adrian Cole
+ */
+@Test(groups = "unit", testName = "LoginCredentialsTest")
+public class LoginCredentialsTest {
+
+   public void testPasswordSetsPrivateKeyToAbsentWhenUnset() {
+      LoginCredentials toTest = LoginCredentials.builder().user("user").password("password").build();
+      assertEquals(toTest.getOptionalPassword(), Optional.of("password"));
+      assertEquals(toTest.getOptionalPrivateKey(), Optional.absent());
+   }
+
+   public void testPasswordLeavesPrivateKeyAloneWhenSet() {
+      LoginCredentials toTest = LoginCredentials.builder().user("user").privateKey("key").password("password").build();
+      assertEquals(toTest.getOptionalPassword(), Optional.of("password"));
+      assertEquals(toTest.getOptionalPrivateKey(), Optional.of("key"));
+   }
+
+   public void testPrivateKeySetsPasswordToAbsentWhenUnset() {
+      LoginCredentials toTest = LoginCredentials.builder().user("user").privateKey("key").build();
+      assertEquals(toTest.getOptionalPassword(), Optional.absent());
+      assertEquals(toTest.getOptionalPrivateKey(), Optional.of("key"));
+   }
+
+   public void testPrivateKeyLeavesPasswordAloneWhenSet() {
+      LoginCredentials toTest = LoginCredentials.builder().user("user").password("password").privateKey("key").build();
+      assertEquals(toTest.getOptionalPassword(), Optional.of("password"));
+      assertEquals(toTest.getOptionalPrivateKey(), Optional.of("key"));
+   }
+}