diff --git a/CHANGES.txt b/CHANGES.txt
index c16988179f6..301d73eff00 100644
--- a/CHANGES.txt
+++ b/CHANGES.txt
@@ -73,6 +73,9 @@ Bug Fixes
 * SOLR-1584: SolrJ - SolrQuery.setIncludeScore() incorrectly added
   fl=score to the parameter list instead of appending score to the
   existing field list. (yonik)
+  
+* SOLR-1580: Solr Configuration ignores 'mergeFactor' parameter, always 
+  uses Lucene default. (Lance Norskog via Mark Miller)
 
 * SOLR-1593: ReverseWildcardFilter didn't work for surrogate pairs
   (i.e. code points outside of the BMP), resulting in incorrect
diff --git a/src/java/org/apache/solr/update/SolrIndexWriter.java b/src/java/org/apache/solr/update/SolrIndexWriter.java
index 26f4bc006c9..f39eecf7c20 100644
--- a/src/java/org/apache/solr/update/SolrIndexWriter.java
+++ b/src/java/org/apache/solr/update/SolrIndexWriter.java
@@ -86,8 +86,9 @@ public class SolrIndexWriter extends IndexWriter {
 
       if (getMergePolicy() instanceof LogMergePolicy) {
         setUseCompoundFile(config.useCompoundFile);
+        if (config.mergeFactor != -1) { setMergeFactor(config.mergeFactor); }
       } else  {
-        log.warn("Use of compound file format cannot be configured if merge policy is not an instance " +
+        log.warn("Use of compound file format or mergefactor cannot be configured if merge policy is not an instance " +
                 "of LogMergePolicy. The configured policy's defaults will be used.");
       }
 
diff --git a/src/test/org/apache/solr/BasicFunctionalityTest.java b/src/test/org/apache/solr/BasicFunctionalityTest.java
index c1a0317b081..35a60416055 100644
--- a/src/test/org/apache/solr/BasicFunctionalityTest.java
+++ b/src/test/org/apache/solr/BasicFunctionalityTest.java
@@ -30,6 +30,7 @@ import org.apache.solr.core.SolrCore;
 import org.apache.solr.search.*;
 import org.apache.solr.handler.*;
 import org.apache.solr.request.*;
+import org.apache.solr.update.SolrIndexWriter;
 import org.apache.solr.util.*;
 import org.apache.solr.schema.*;
 
@@ -112,6 +113,11 @@ public class BasicFunctionalityTest extends AbstractSolrTestCase {
   }
 
   public void testSomeStuff() throws Exception {
+	// test merge factor picked up
+	SolrCore core = h.getCore();
+	SolrIndexWriter writer = new SolrIndexWriter("testWriter",core.getNewIndexDir(), core.getDirectoryFactory(), false, core.getSchema(), core.getSolrConfig().mainIndexConfig, core.getDeletionPolicy());
+	assertEquals("Mergefactor was not picked up", writer.getMergeFactor(), 8);
+	  
     lrf.args.put("version","2.0");
     assertQ("test query on empty index",
             req("qlkciyopsbgzyvkylsjhchghjrdf")
diff --git a/src/test/test-files/solr/conf/solrconfig.xml b/src/test/test-files/solr/conf/solrconfig.xml
index 290a84f1d6d..d25e0422805 100644
--- a/src/test/test-files/solr/conf/solrconfig.xml
+++ b/src/test/test-files/solr/conf/solrconfig.xml
@@ -102,7 +102,7 @@
   <mainIndex>
     <!-- lucene options specific to the main on-disk lucene index -->
     <useCompoundFile>false</useCompoundFile>
-    <mergeFactor>10</mergeFactor>
+    <mergeFactor>8</mergeFactor>
     <!-- for better multi-segment testing, we are using slower
     indexing properties of maxBufferedDocs=10 and LogDocMergePolicy.
     -->