diff --git a/icu4j/src/com/ibm/icu/dev/test/util/ICUResourceBundleTest.java b/icu4j/src/com/ibm/icu/dev/test/util/ICUResourceBundleTest.java
index 7dd687c80c3..4a88f636f2a 100644
--- a/icu4j/src/com/ibm/icu/dev/test/util/ICUResourceBundleTest.java
+++ b/icu4j/src/com/ibm/icu/dev/test/util/ICUResourceBundleTest.java
@@ -52,6 +52,14 @@ public final class ICUResourceBundleTest extends TestFmwk {
         }
         
         
+    }
+    public void TestJB3879(){
+        // this tests tests loading of root bundle when a resource bundle 
+        // for the default locale is requested 
+    	ICUResourceBundle bundle = (ICUResourceBundle) UResourceBundle.getBundleInstance("com/ibm/icu/dev/data/testdata", ULocale.getDefault());
+        if(bundle==null){
+        	errln("could not create the resource bundle");
+        }
     }
     public void TestOpen(){
         ICUResourceBundle bundle = (ICUResourceBundle) UResourceBundle.getBundleInstance(ICUResourceBundle.ICU_BASE_NAME, "en_US_POSIX", ICUData.class.getClassLoader());
diff --git a/icu4j/src/com/ibm/icu/util/UResourceBundle.java b/icu4j/src/com/ibm/icu/util/UResourceBundle.java
index 8dc25731e3e..03b116d8246 100644
--- a/icu4j/src/com/ibm/icu/util/UResourceBundle.java
+++ b/icu4j/src/com/ibm/icu/util/UResourceBundle.java
@@ -415,6 +415,8 @@ public abstract class UResourceBundle extends ResourceBundle{
                 }else{
                     if(defaultID.indexOf(localeName)==-1){
                         b = instantiateICUResource(baseName, defaultID, root);   
+                    }else if(rootLocale.length()!=0){
+                    	b = ICUResourceBundle.createBundle(baseName, rootLocale, root);
                     }
                 }
             }else{