1 files changed, 10 insertions, 2 deletions

diff --git a/src/cuchaz/enigma/convert/ClassMatching.java b/src/cuchaz/enigma/convert/ClassMatching.java
index 9f93130..d8973ac 100644
--- a/src/cuchaz/enigma/convert/ClassMatching.java
+++ b/src/cuchaz/enigma/convert/ClassMatching.java
@@ -40,8 +40,16 @@ public class ClassMatching {
         }
         
         public void match(Iterable<ClassEntry> sourceClasses, Iterable<ClassEntry> destClasses) {
-                m_sourceClasses.addAll(sourceClasses);
-                m_destClasses.addAll(destClasses);
+                for (ClassEntry sourceClass : sourceClasses) {
+                        if (!m_knownMatches.containsKey(sourceClass)) {
+                                m_sourceClasses.add(sourceClass);
+                        }
+                }
+                for (ClassEntry destClass : destClasses) {
+                        if (!m_knownMatches.containsValue(destClass)) {
+                                m_destClasses.add(destClass);
+                        }
+                }
         }
         
         public Collection<ClassMatch> matches() {