diff --git a/classpath/java/lang/Class.java b/classpath/java/lang/Class.java
index 225680a66b..59099310dc 100644
--- a/classpath/java/lang/Class.java
+++ b/classpath/java/lang/Class.java
@@ -105,7 +105,7 @@ public final class Class <T> {
 
   public Class getComponentType() {
     if (isArray()) {
-      return (Class) (Object) staticTable;
+      return (Class) staticTable;
     } else {
       return null;
     }
@@ -279,9 +279,10 @@ public final class Class <T> {
   public Field[] getFields() {
     Field[] array = new Field[countPublicFields()];
     if (fieldTable != null) {
+      int ai = 0;
       for (int i = 0; i < fieldTable.length; ++i) {
         if (((fieldTable[i].getModifiers() & Modifier.PUBLIC)) != 0) {
-          array[i] = fieldTable[i];
+          array[ai++] = fieldTable[i];
         }
       }
     }
@@ -306,10 +307,10 @@ public final class Class <T> {
   public Method[] getDeclaredMethods() {
     Method[] array = new Method[countMethods(false)];
     if (methodTable != null) {
-      int index = 0;
+      int ai = 0;
       for (int i = 0; i < methodTable.length; ++i) {
         if (! methodTable[i].getName().startsWith("<")) {
-          array[index++] = methodTable[i];
+          array[ai++] = methodTable[i];
         }
       }
     }
@@ -346,7 +347,7 @@ public final class Class <T> {
   }
 
   public T[] getEnumConstants() {
-    if (isAssignableFrom(Enum.class)) {
+    if (Enum.class.isAssignableFrom(this)) {
       try {
         return (T[]) getMethod("values").invoke(null);
       } catch (Exception e) {
@@ -374,7 +375,7 @@ public final class Class <T> {
   }
 
   public boolean isInstance(Object o) {
-    return isAssignableFrom(o.getClass());
+    return o != null && isAssignableFrom(o.getClass());
   }
 
   public boolean isPrimitive() {
diff --git a/classpath/java/lang/reflect/Array.java b/classpath/java/lang/reflect/Array.java
index 06d99e20d3..4d8f7c2515 100644
--- a/classpath/java/lang/reflect/Array.java
+++ b/classpath/java/lang/reflect/Array.java
@@ -68,10 +68,14 @@ public final class Array {
       break;
     case 'L':
     case '[':
-      if (array.getClass().getComponentType().isInstance(value)) {
+      if (value == null
+          || array.getClass().getComponentType().isInstance(value))
+      {
         ((Object[]) array)[index] = value;
       } else {
-        throw new IllegalArgumentException();
+        throw new IllegalArgumentException
+          ("need " + array.getClass().getComponentType() +
+           ", got " + value.getClass().getName());
       }
       break;
 
diff --git a/classpath/java/lang/reflect/Field.java b/classpath/java/lang/reflect/Field.java
index 22bf1c9af7..2b2bacfbdc 100644
--- a/classpath/java/lang/reflect/Field.java
+++ b/classpath/java/lang/reflect/Field.java
@@ -43,7 +43,7 @@ public class Field<T> extends AccessibleObject {
   }
 
   public Class getType() {
-    return Class.forCanonicalName(getName());
+    return Class.forCanonicalName(new String(spec, 0, spec.length - 1, false));
   }
 
   public Object get(Object instance) throws IllegalAccessException {
@@ -139,10 +139,11 @@ public class Field<T> extends AccessibleObject {
       break;
 
     case ObjectField:
-      if (getType().isInstance(value)) {
+      if (value == null || getType().isInstance(value)) {
         setObject(target, offset, value);
       } else {
-        throw new IllegalArgumentException();
+        throw new IllegalArgumentException
+          ("need " + getType() + ", got " + value.getClass().getName());
       }
       break;