diff --git a/java/src/org/broadinstitute/sting/gatk/walkers/recalibration/RecalDataManager.java b/java/src/org/broadinstitute/sting/gatk/walkers/recalibration/RecalDataManager.java
index 8092f8c1a..3bb6ee3f2 100644
--- a/java/src/org/broadinstitute/sting/gatk/walkers/recalibration/RecalDataManager.java
+++ b/java/src/org/broadinstitute/sting/gatk/walkers/recalibration/RecalDataManager.java
@@ -250,9 +250,13 @@ public class RecalDataManager {
             ((GATKSAMRecord)read).setReadGroup( readGroup );
         }
 
-        if( RAC.FORCE_PLATFORM != null && !readGroup.getPlatform().equals(RAC.FORCE_PLATFORM)) {
+        if( RAC.FORCE_PLATFORM != null && (readGroup.getPlatform() == null || !readGroup.getPlatform().equals(RAC.FORCE_PLATFORM))) {
             readGroup.setPlatform( RAC.FORCE_PLATFORM );
         }
+
+        if ( readGroup.getPlatform() == null ) {
+            readGroup.setPlatform( RAC.DEFAULT_PLATFORM );            
+        }
     }
 
     /**