diff --git a/core/src/main/java/org/ocpsoft/prettytime/TimeFormat.java b/core/src/main/java/org/ocpsoft/prettytime/TimeFormat.java
index 35f806e..f3b2759 100644
--- a/core/src/main/java/org/ocpsoft/prettytime/TimeFormat.java
+++ b/core/src/main/java/org/ocpsoft/prettytime/TimeFormat.java
@@ -25,14 +25,14 @@ public interface TimeFormat
    /**
     * Given a populated {@link Duration} object. Apply formatting (with rounding) and output the result.
     * 
-    * @param The original {@link Duration} instance from which the time string should be decorated.
+    * @param duration The original {@link Duration} instance from which the time string should be decorated.
     */
    public abstract String format(final Duration duration);
 
    /**
     * Given a populated {@link Duration} object. Apply formatting (without rounding) and output the result.
     * 
-    * @param The original {@link Duration} instance from which the time string should be decorated.
+    * @param duration The original {@link Duration} instance from which the time string should be decorated.
     */
    public String formatUnrounded(Duration duration);
 
@@ -52,4 +52,4 @@ public interface TimeFormat
     */
    public String decorateUnrounded(Duration duration, String time);
 
-}
\ No newline at end of file
+}