diff --git a/Core/src/org/sleuthkit/autopsy/modules/interestingitems/FilesSet.java b/Core/src/org/sleuthkit/autopsy/modules/interestingitems/FilesSet.java
index d71190ad2a..d3c8cc0cc7 100755
--- a/Core/src/org/sleuthkit/autopsy/modules/interestingitems/FilesSet.java
+++ b/Core/src/org/sleuthkit/autopsy/modules/interestingitems/FilesSet.java
@@ -150,6 +150,9 @@ final class FilesSet {
          * @param pathFilter A file path filter, may be null.
          */
         Rule(String ruleName, FileNameFilter fileNameFilter, MetaTypeFilter metaTypeFilter, ParentPathFilter pathFilter) {
+            if (ruleName == null) {
+                throw new NullPointerException("Interesting files set rule name cannot be null");
+            }
             if (fileNameFilter == null) {
                 throw new IllegalArgumentException("Interesting files set rule file name filter cannot be null");
             }
diff --git a/Core/src/org/sleuthkit/autopsy/modules/interestingitems/InterestingItemDefsManager.java b/Core/src/org/sleuthkit/autopsy/modules/interestingitems/InterestingItemDefsManager.java
index 735683cc58..6980c0ff51 100755
--- a/Core/src/org/sleuthkit/autopsy/modules/interestingitems/InterestingItemDefsManager.java
+++ b/Core/src/org/sleuthkit/autopsy/modules/interestingitems/InterestingItemDefsManager.java
@@ -402,11 +402,6 @@ final class InterestingItemDefsManager extends Observable {
         private static String readRuleName(Element elem) {
             // The rule must have a name. 
             String ruleName = elem.getAttribute(FilesSetXML.NAME_ATTR);
-            if (ruleName.isEmpty()) {
-                // Assume a TSK Framework definitions file is being read and 
-                // synthesize a rule name.
-                ruleName = UNNAMED_LEGACY_RULE_PREFIX + Integer.toString(FilesSetXML.unnamedLegacyRuleCounter++);
-            }
             return ruleName;
         }
 
diff --git a/Core/src/org/sleuthkit/autopsy/modules/interestingitems/InterestingItemDefsPanel.java b/Core/src/org/sleuthkit/autopsy/modules/interestingitems/InterestingItemDefsPanel.java
index 046e641058..993039f601 100755
--- a/Core/src/org/sleuthkit/autopsy/modules/interestingitems/InterestingItemDefsPanel.java
+++ b/Core/src/org/sleuthkit/autopsy/modules/interestingitems/InterestingItemDefsPanel.java
@@ -306,7 +306,7 @@ final class InterestingItemDefsPanel extends IngestModuleGlobalSettingsPanel imp
                 rules.remove(selectedRule.getName());
             }
             FilesSet.Rule newRule = new FilesSet.Rule(panel.getRuleName(), panel.getFileNameFilter(), panel.getMetaTypeFilter(), panel.getPathFilter());
-            rules.put(newRule.toString(), newRule);
+            rules.put(Integer.toString(newRule.hashCode()), newRule);
 
             // Add the new/edited files set definition, replacing any previous 
             // definition with the same name and refreshing the display.