diff --git a/source/net/sourceforge/filebot/similarity/EpisodeMetrics.java b/source/net/sourceforge/filebot/similarity/EpisodeMetrics.java
index 4be554a4..b5e34573 100644
--- a/source/net/sourceforge/filebot/similarity/EpisodeMetrics.java
+++ b/source/net/sourceforge/filebot/similarity/EpisodeMetrics.java
@@ -407,7 +407,8 @@ public enum EpisodeMetrics implements SimilarityMetric {
 		@Override
 		public float getSimilarity(Object o1, Object o2) {
 			// adjust differentiation accuracy to about a year
-			return super.getSimilarity(o1, o2) >= 0.8 ? 1 : 0;
+			float f = super.getSimilarity(o1, o2);
+			return f >= 0.9 ? 1 : f >= 0 ? 0 : -1;
 		}
 		
 		
diff --git a/source/net/sourceforge/filebot/similarity/TimeStampMetric.java b/source/net/sourceforge/filebot/similarity/TimeStampMetric.java
index b5deceff..954fc56a 100644
--- a/source/net/sourceforge/filebot/similarity/TimeStampMetric.java
+++ b/source/net/sourceforge/filebot/similarity/TimeStampMetric.java
@@ -17,7 +17,7 @@ public class TimeStampMetric implements SimilarityMetric {
 		long t2 = getTimeStamp(o2);
 		
 		if (t1 <= 0 || t2 <= 0)
-			return 0;
+			return -1;
 		
 		float min = min(t1, t2);
 		float max = max(t1, t2);