diff --git a/src/main/java/net/md_5/specialsource/JarMapping.java b/src/main/java/net/md_5/specialsource/JarMapping.java
index 03d0f40..63292cf 100644
--- a/src/main/java/net/md_5/specialsource/JarMapping.java
+++ b/src/main/java/net/md_5/specialsource/JarMapping.java
@@ -266,6 +266,7 @@ public class JarMapping {
 
             if (oldClassName.endsWith("/")) {
                 // Special case: mapping an entire hierarchy of classes
+                // TODO: support default package, '.' in .srg
                 packages.put(oldClassName.substring(0, oldClassName.length() - 1), newClassName);
             } else {
                 classes.put(oldClassName, newClassName);
@@ -319,23 +320,30 @@ public class JarMapping {
                 classes.put(oldClassName, newClassName);
             }
         } else if (kind.equals("PK:")) {
-            /* TODO: support .srg's package maps properly - not simply prefix matches(?)
-             String oldPackageName = inputTransformer.transformClassName(tokens[1]);
-             String newPackageName = outputTransformer.transformClassName(tokens[2]);
+            String oldPackageName = inputTransformer.transformClassName(tokens[1]);
+            String newPackageName = outputTransformer.transformClassName(tokens[2]);
 
-             if (reverse) {
-                 String temp = newPackageName;
-                 newPackageName = oldPackageName;
-                 oldPackageName = temp;
-             }
+            if (reverse) {
+                String temp = newPackageName;
+                newPackageName = oldPackageName;
+                oldPackageName = temp;
+            }
 
-             if (packages.containsKey(oldPackageName) && !newPackageName.equals(packages.get(oldPackageName))) {
-                 throw new IllegalArgumentException("Duplicate package mapping: " + oldPackageName + " ->" + newPackageName +
-                 " but already mapped to "+packages.get(oldPackageName)+" in line="+line);
-             }
+            // package names always either 1) suffixed with '/', or 2) equal to '.' to signify default package
+            if (!newPackageName.equals(".") && !newPackageName.endsWith("/")) {
+                newPackageName += "/";
+            }
 
-             packages.put(oldPackageName, newPackageName);
-             */
+            if (!oldPackageName.equals(".") && !oldPackageName.endsWith("/")) {
+                oldPackageName += "/";
+            }
+
+            if (packages.containsKey(oldPackageName) && !newPackageName.equals(packages.get(oldPackageName))) {
+                throw new IllegalArgumentException("Duplicate package mapping: " + oldPackageName + " ->" + newPackageName +
+                " but already mapped to "+packages.get(oldPackageName)+" in line="+line);
+            }
+
+            packages.put(oldPackageName, newPackageName);
         } else if (kind.equals("FD:")) {
             String oldFull = tokens[1];
             String newFull = tokens[2];
diff --git a/src/main/java/net/md_5/specialsource/JarRemapper.java b/src/main/java/net/md_5/specialsource/JarRemapper.java
index 147b66d..6ad3f4f 100644
--- a/src/main/java/net/md_5/specialsource/JarRemapper.java
+++ b/src/main/java/net/md_5/specialsource/JarRemapper.java
@@ -101,19 +101,52 @@ public class JarRemapper extends Remapper {
      * Helper method to map a class name by package (prefix) or class (exact)
      */
     private static String mapClassName(String className, Map<String, String> packageMap, Map<String, String> classMap) {
+        if (classMap != null && classMap.containsKey(className)) {
+            return classMap.get(className);
+        }
+
         if (packageMap != null) {
             Iterator<String> iter = packageMap.keySet().iterator();
             while (iter.hasNext()) {
                 String oldPackage = iter.next();
-                if (className.startsWith(oldPackage)) {
+                if (matchClassPackage(oldPackage, className)) {
                     String newPackage = packageMap.get(oldPackage);
 
-                    return newPackage + className.substring(oldPackage.length());
+                    return moveClassPackage(newPackage, getSimpleName(oldPackage, className));
                 }
             }
         }
 
-        return classMap != null ? classMap.get(className) : null;
+        return null;
+    }
+
+    private static boolean matchClassPackage(String packageName, String className) {
+        if (packageName.equals(".")) {
+            return isDefaultPackage(className);
+        }
+
+        return className.startsWith(packageName);
+    }
+
+    private static String moveClassPackage(String packageName, String classSimpleName) {
+        if (packageName.equals(".")) {
+            System.out.println("moveClassPackage(.) "+classSimpleName);
+            return classSimpleName;
+        }
+
+        return packageName + classSimpleName;
+    }
+
+    private static boolean isDefaultPackage(String className) {
+        return className.indexOf('/') == -1;
+    }
+
+    private static String getSimpleName(String oldPackage, String className) {
+        if (oldPackage.equals(".")) {
+            return className;
+        }
+
+        return className.substring(oldPackage.length());
     }
 
     @Override