diff --git a/commons/src/main/java/org/archive/util/SurtPrefixSet.java b/commons/src/main/java/org/archive/util/SurtPrefixSet.java
index e2e4825d..4275cb7a 100644
--- a/commons/src/main/java/org/archive/util/SurtPrefixSet.java
+++ b/commons/src/main/java/org/archive/util/SurtPrefixSet.java
@@ -132,14 +132,14 @@ public class SurtPrefixSet extends PrefixSet {
     
 
     /**
-     * Interpret the given line as a directive, returning true if it
-     * was meaningful. 
+     * Interpret the given SURT/URI/host as a directive, returning true 
+     * if it was meaningful. 
      * 
-     * @param line potential directive
+     * @param suri potential directive
      * @return boolean true if applied as directive, false otherwise
      */
-    public boolean considerAsAddDirective(String line) {
-        String u = line.trim();
+    public boolean considerAsAddDirective(String suri) {
+        String u = suri.trim();
         if(u.length()==0) {
             // empty string: consider a mistake
             return false; 
diff --git a/modules/src/main/java/org/archive/modules/deciderules/surt/SurtPrefixedDecideRule.java b/modules/src/main/java/org/archive/modules/deciderules/surt/SurtPrefixedDecideRule.java
index fd40cd8f..50a692b2 100644
--- a/modules/src/main/java/org/archive/modules/deciderules/surt/SurtPrefixedDecideRule.java
+++ b/modules/src/main/java/org/archive/modules/deciderules/surt/SurtPrefixedDecideRule.java
@@ -274,7 +274,7 @@ implements
     public boolean nonseedLine(String line) {
         String effectiveDirective = getEffectiveAddDirective();
         if(line.startsWith(effectiveDirective)) {
-            return surtPrefixes.considerAsAddDirective(line);
+            return surtPrefixes.considerAsAddDirective(line.substring(effectiveDirective.length()));
         } else {
             // not a line this instance is interested in
             return false;