diff --git a/spring-webflow/src/main/java/org/springframework/webflow/conversation/impl/BadlyFormattedConversationIdException.java b/spring-webflow/src/main/java/org/springframework/webflow/conversation/impl/BadlyFormattedConversationIdException.java
new file mode 100644
index 00000000..a31db19e
--- /dev/null
+++ b/spring-webflow/src/main/java/org/springframework/webflow/conversation/impl/BadlyFormattedConversationIdException.java
@@ -0,0 +1,20 @@
+package org.springframework.webflow.conversation.impl;
+
+import org.springframework.webflow.conversation.ConversationException;
+
+/**
+ * Thrown if a conversation id could not be parsed.
+ * 
+ * @author Keith Donald
+ */
+public class BadlyFormattedConversationIdException extends ConversationException {
+
+	/**
+	 * Creates a new badly formatted conversation id exception.
+	 * @param encodedId the badly formatted id
+	 * @param parseException the cause
+	 */
+	public BadlyFormattedConversationIdException(String encodedId, Throwable parseException) {
+		super("Unable to parse string-encoded conversationId + '" + encodedId + "'", parseException);
+	}
+}
diff --git a/spring-webflow/src/main/java/org/springframework/webflow/conversation/impl/LockInterruptedException.java b/spring-webflow/src/main/java/org/springframework/webflow/conversation/impl/LockInterruptedException.java
new file mode 100644
index 00000000..37faa6e5
--- /dev/null
+++ b/spring-webflow/src/main/java/org/springframework/webflow/conversation/impl/LockInterruptedException.java
@@ -0,0 +1,20 @@
+package org.springframework.webflow.conversation.impl;
+
+import org.springframework.webflow.conversation.ConversationLockException;
+
+/**
+ * <code>Exception</code> indicating that some {@link Thread} was {@link Thread#interrupt() interrupted} during
+ * processing and as such processing was halted.
+ * <p>
+ * Only used to wrap the checked {@link InterruptedException java.lang.InterruptedException}.
+ */
+public class LockInterruptedException extends ConversationLockException {
+
+	/**
+	 * Creates a new <code>SystemInterruptedException</code>.
+	 * @param cause the root cause of this <code>Exception</code>
+	 */
+	public LockInterruptedException(InterruptedException cause) {
+		super("Unable to acquire conversation lock - thread interrupted", cause);
+	}
+}
\ No newline at end of file
diff --git a/spring-webflow/src/main/java/org/springframework/webflow/conversation/impl/LockTimeoutException.java b/spring-webflow/src/main/java/org/springframework/webflow/conversation/impl/LockTimeoutException.java
new file mode 100644
index 00000000..79ff6500
--- /dev/null
+++ b/spring-webflow/src/main/java/org/springframework/webflow/conversation/impl/LockTimeoutException.java
@@ -0,0 +1,16 @@
+package org.springframework.webflow.conversation.impl;
+
+import org.springframework.webflow.conversation.ConversationLockException;
+
+/**
+ * Thrown when a lock could not be acquired after a timeout period.
+ * 
+ * @author Keith Donald
+ */
+public class LockTimeoutException extends ConversationLockException {
+
+	public LockTimeoutException(int timeoutSeconds) {
+		super("Unable to acquire conversation lock after " + timeoutSeconds + " seconds");
+	}
+
+}