diff --git a/spring-cloud-sleuth-core/src/main/java/org/springframework/cloud/sleuth/trace/IdGenerator.java b/spring-cloud-sleuth-core/src/main/java/org/springframework/cloud/sleuth/trace/IdGenerator.java
new file mode 100644
index 000000000..239833367
--- /dev/null
+++ b/spring-cloud-sleuth-core/src/main/java/org/springframework/cloud/sleuth/trace/IdGenerator.java
@@ -0,0 +1,8 @@
+package org.springframework.cloud.sleuth.trace;
+
+/**
+ * @author Spencer Gibb
+ */
+public interface IdGenerator {
+	String create();
+}
diff --git a/spring-cloud-sleuth-core/src/main/java/org/springframework/cloud/sleuth/trace/Span.java b/spring-cloud-sleuth-core/src/main/java/org/springframework/cloud/sleuth/trace/Span.java
index 673b0d6be..c1974b74f 100644
--- a/spring-cloud-sleuth-core/src/main/java/org/springframework/cloud/sleuth/trace/Span.java
+++ b/spring-cloud-sleuth-core/src/main/java/org/springframework/cloud/sleuth/trace/Span.java
@@ -1,6 +1,5 @@
 package org.springframework.cloud.sleuth.trace;
 
-import java.util.Collection;
 import java.util.List;
 import java.util.Map;
 
diff --git a/spring-cloud-sleuth-core/src/main/java/org/springframework/cloud/sleuth/trace/Trace.java b/spring-cloud-sleuth-core/src/main/java/org/springframework/cloud/sleuth/trace/Trace.java
index 6c1f57ea4..b6a1f2dd5 100644
--- a/spring-cloud-sleuth-core/src/main/java/org/springframework/cloud/sleuth/trace/Trace.java
+++ b/spring-cloud-sleuth-core/src/main/java/org/springframework/cloud/sleuth/trace/Trace.java
@@ -47,9 +47,9 @@ public interface Trace {
 	 *
 	 * @param description The description field for the new span to create.
 	 */
-	public TraceScope startSpan(String description);
+	TraceScope startSpan(String description);
 
-	public TraceScope startSpan(String description, TraceInfo tinfo);
+	TraceScope startSpan(String description, TraceInfo tinfo);
 
 	/**
 	 * Creates a new trace scope.
@@ -60,33 +60,33 @@ public interface Trace {
 	 *
 	 * @param description The description field for the new span to create.
 	 */
-	public TraceScope startSpan(String description, Span parent);
+	TraceScope startSpan(String description, Span parent);
 
-	public <T> TraceScope startSpan(String description, Sampler<T> s);
+	<T> TraceScope startSpan(String description, Sampler<T> s);
 
-	public <T> TraceScope startSpan(String description, Sampler<T> s, T info);
+	<T> TraceScope startSpan(String description, Sampler<T> s, T info);
 
 	/**
 	 * Pick up an existing span from another thread.
 	 */
-	public TraceScope continueSpan(Span s);
+	TraceScope continueSpan(Span s);
 
 	/**
 	 * Adds a data annotation to the current span if tracing is currently on.
 	 */
-	public void addKVAnnotation(String key, String value);
+	void addKVAnnotation(String key, String value);
 
 	/**
 	 * Returns true if the current thread is a part of a trace, false otherwise.
 	 */
-	public boolean isTracing();
+	boolean isTracing();
 
 	/**
 	 * If we are tracing, return the current span, else null
 	 *
 	 * @return Span representing the current trace, or null if not tracing.
 	 */
-	public Span currentSpan();
+	Span currentSpan();
 
-	public void setSpanReceivers(Collection<SpanReceiver> spanReceivers);
+	void setSpanReceivers(Collection<SpanReceiver> spanReceivers);
 }
diff --git a/spring-cloud-sleuth-core/src/main/java/org/springframework/cloud/sleuth/trace/TraceInfo.java b/spring-cloud-sleuth-core/src/main/java/org/springframework/cloud/sleuth/trace/TraceInfo.java
index 4a9f059dd..31c8e5dab 100644
--- a/spring-cloud-sleuth-core/src/main/java/org/springframework/cloud/sleuth/trace/TraceInfo.java
+++ b/spring-cloud-sleuth-core/src/main/java/org/springframework/cloud/sleuth/trace/TraceInfo.java
@@ -7,6 +7,6 @@ import lombok.Data;
  */
 @Data
 public class TraceInfo {
-	private final long traceId;
-	private final long spanId;
+	private final String traceId;
+	private final String spanId;
 }