diff --git a/src/main/java/org/apache/commons/collections4/comparators/ComparableComparator.java b/src/main/java/org/apache/commons/collections4/comparators/ComparableComparator.java
index 1d82514d8..9a2715ba5 100644
--- a/src/main/java/org/apache/commons/collections4/comparators/ComparableComparator.java
+++ b/src/main/java/org/apache/commons/collections4/comparators/ComparableComparator.java
@@ -46,7 +46,7 @@ public class ComparableComparator<E extends Comparable<? super E>> implements Co
 
     /** The singleton instance. */
     @SuppressWarnings("rawtypes")
-    public static final ComparableComparator<?> INSTANCE = new ComparableComparator();
+    public static final ComparableComparator INSTANCE = new ComparableComparator();
 
     //-----------------------------------------------------------------------
     /**
diff --git a/src/main/java/org/apache/commons/collections4/functors/CloneTransformer.java b/src/main/java/org/apache/commons/collections4/functors/CloneTransformer.java
index cfc7514fd..d99d492ba 100644
--- a/src/main/java/org/apache/commons/collections4/functors/CloneTransformer.java
+++ b/src/main/java/org/apache/commons/collections4/functors/CloneTransformer.java
@@ -34,7 +34,8 @@ public class CloneTransformer<T> implements Transformer<T, T>, Serializable {
     private static final long serialVersionUID = -8188742709499652567L;
 
     /** Singleton predicate instance */
-    public static final Transformer<Object, Object> INSTANCE = new CloneTransformer<Object>();
+    @SuppressWarnings("rawtypes") // the singleton instance works for all types
+    public static final Transformer INSTANCE = new CloneTransformer<Object>();
 
     /**
      * Factory returning the singleton instance.
diff --git a/src/main/java/org/apache/commons/collections4/functors/ConstantFactory.java b/src/main/java/org/apache/commons/collections4/functors/ConstantFactory.java
index 0b05586a3..76a45796d 100644
--- a/src/main/java/org/apache/commons/collections4/functors/ConstantFactory.java
+++ b/src/main/java/org/apache/commons/collections4/functors/ConstantFactory.java
@@ -36,7 +36,8 @@ public class ConstantFactory<T> implements Factory<T>, Serializable {
     private static final long serialVersionUID = -3520677225766901240L;
 
     /** Returns null each time */
-    public static final Factory<Object> NULL_INSTANCE = new ConstantFactory<Object>(null);
+    @SuppressWarnings("rawtypes") // The null factory works for all object types
+    public static final Factory NULL_INSTANCE = new ConstantFactory<Object>(null);
 
     /** The closures to call in turn */
     private final T iConstant;
diff --git a/src/main/java/org/apache/commons/collections4/functors/ConstantTransformer.java b/src/main/java/org/apache/commons/collections4/functors/ConstantTransformer.java
index d1ffdadeb..bc3c4d9ca 100644
--- a/src/main/java/org/apache/commons/collections4/functors/ConstantTransformer.java
+++ b/src/main/java/org/apache/commons/collections4/functors/ConstantTransformer.java
@@ -36,7 +36,8 @@ public class ConstantTransformer<I, O> implements Transformer<I, O>, Serializabl
     private static final long serialVersionUID = 6374440726369055124L;
 
     /** Returns null each time */
-    public static final Transformer<Object, Object> NULL_INSTANCE = new ConstantTransformer<Object, Object>(null);
+    @SuppressWarnings("rawtypes")
+    public static final Transformer NULL_INSTANCE = new ConstantTransformer<Object, Object>(null);
 
     /** The closures to call in turn */
     private final O iConstant;
diff --git a/src/main/java/org/apache/commons/collections4/functors/DefaultEquator.java b/src/main/java/org/apache/commons/collections4/functors/DefaultEquator.java
index d6acdde4a..1111e2ee1 100644
--- a/src/main/java/org/apache/commons/collections4/functors/DefaultEquator.java
+++ b/src/main/java/org/apache/commons/collections4/functors/DefaultEquator.java
@@ -33,7 +33,8 @@ public class DefaultEquator<T> implements Equator<T>, Serializable {
     private static final long serialVersionUID = 825802648423525485L;
 
     /** Static instance */
-    public static final DefaultEquator<Object> INSTANCE = new DefaultEquator<Object>();
+    @SuppressWarnings("rawtypes") // the static instance works for all types
+    public static final DefaultEquator INSTANCE = new DefaultEquator<Object>();
 
     /**
      * Hashcode used for <code>null</code> objects.
diff --git a/src/main/java/org/apache/commons/collections4/functors/ExceptionClosure.java b/src/main/java/org/apache/commons/collections4/functors/ExceptionClosure.java
index 9f131740e..87bfbde3d 100644
--- a/src/main/java/org/apache/commons/collections4/functors/ExceptionClosure.java
+++ b/src/main/java/org/apache/commons/collections4/functors/ExceptionClosure.java
@@ -33,7 +33,8 @@ public final class ExceptionClosure<E> implements Closure<E>, Serializable {
     private static final long serialVersionUID = 7179106032121985545L;
 
     /** Singleton predicate instance */
-    public static final Closure<Object> INSTANCE = new ExceptionClosure<Object>();
+    @SuppressWarnings("rawtypes") // the static instance works for all types
+    public static final Closure INSTANCE = new ExceptionClosure<Object>();
 
     /**
      * Factory returning the singleton instance.
diff --git a/src/main/java/org/apache/commons/collections4/functors/ExceptionFactory.java b/src/main/java/org/apache/commons/collections4/functors/ExceptionFactory.java
index 4512eb773..7889f92ce 100644
--- a/src/main/java/org/apache/commons/collections4/functors/ExceptionFactory.java
+++ b/src/main/java/org/apache/commons/collections4/functors/ExceptionFactory.java
@@ -33,7 +33,8 @@ public final class ExceptionFactory<T> implements Factory<T>, Serializable {
     private static final long serialVersionUID = 7179106032121985545L;
 
     /** Singleton predicate instance */
-    public static final Factory<Object> INSTANCE = new ExceptionFactory<Object>();
+    @SuppressWarnings("rawtypes") // the static instance works for all types
+    public static final Factory INSTANCE = new ExceptionFactory<Object>();
 
     /**
      * Factory returning the singleton instance.
diff --git a/src/main/java/org/apache/commons/collections4/functors/ExceptionPredicate.java b/src/main/java/org/apache/commons/collections4/functors/ExceptionPredicate.java
index c661b3407..d899c4ad3 100644
--- a/src/main/java/org/apache/commons/collections4/functors/ExceptionPredicate.java
+++ b/src/main/java/org/apache/commons/collections4/functors/ExceptionPredicate.java
@@ -33,7 +33,8 @@ public final class ExceptionPredicate<T> implements Predicate<T>, Serializable {
     private static final long serialVersionUID = 7179106032121985545L;
 
     /** Singleton predicate instance */
-    public static final Predicate<Object> INSTANCE = new ExceptionPredicate<Object>();
+    @SuppressWarnings("rawtypes") // the static instance works for all types
+    public static final Predicate INSTANCE = new ExceptionPredicate<Object>();
 
     /**
      * Factory returning the singleton instance.
diff --git a/src/main/java/org/apache/commons/collections4/functors/ExceptionTransformer.java b/src/main/java/org/apache/commons/collections4/functors/ExceptionTransformer.java
index 2c4ad591b..e7658a1e5 100644
--- a/src/main/java/org/apache/commons/collections4/functors/ExceptionTransformer.java
+++ b/src/main/java/org/apache/commons/collections4/functors/ExceptionTransformer.java
@@ -33,7 +33,8 @@ public final class ExceptionTransformer<I, O> implements Transformer<I, O>, Seri
     private static final long serialVersionUID = 7179106032121985545L;
 
     /** Singleton predicate instance */
-    public static final Transformer<Object, Object> INSTANCE = new ExceptionTransformer<Object, Object>();
+    @SuppressWarnings("rawtypes") // the static instance works for all types
+    public static final Transformer INSTANCE = new ExceptionTransformer<Object, Object>();
 
     /**
      * Factory returning the singleton instance.
diff --git a/src/main/java/org/apache/commons/collections4/functors/FalsePredicate.java b/src/main/java/org/apache/commons/collections4/functors/FalsePredicate.java
index 1061b9a60..005379309 100644
--- a/src/main/java/org/apache/commons/collections4/functors/FalsePredicate.java
+++ b/src/main/java/org/apache/commons/collections4/functors/FalsePredicate.java
@@ -32,7 +32,8 @@ public final class FalsePredicate<T> implements Predicate<T>, Serializable {
     private static final long serialVersionUID = 7533784454832764388L;
 
     /** Singleton predicate instance */
-    public static final Predicate<Object> INSTANCE = new FalsePredicate<Object>();
+    @SuppressWarnings("rawtypes") // the static instance works for all types
+    public static final Predicate INSTANCE = new FalsePredicate<Object>();
 
     /**
      * Get a typed instance.
diff --git a/src/main/java/org/apache/commons/collections4/functors/IfClosure.java b/src/main/java/org/apache/commons/collections4/functors/IfClosure.java
index 4d9aafee4..4b39c9457 100644
--- a/src/main/java/org/apache/commons/collections4/functors/IfClosure.java
+++ b/src/main/java/org/apache/commons/collections4/functors/IfClosure.java
@@ -91,7 +91,7 @@ public class IfClosure<E> implements Closure<E>, Serializable {
      * @since 3.2
      */
     public IfClosure(final Predicate<? super E> predicate, final Closure<? super E> trueClosure) {
-        this(predicate, trueClosure, NOPClosure.INSTANCE);
+        this(predicate, trueClosure, NOPClosure.nopClosure());
     }
 
     /**
diff --git a/src/main/java/org/apache/commons/collections4/functors/InstantiateTransformer.java b/src/main/java/org/apache/commons/collections4/functors/InstantiateTransformer.java
index 4961f3234..8d947e3bb 100644
--- a/src/main/java/org/apache/commons/collections4/functors/InstantiateTransformer.java
+++ b/src/main/java/org/apache/commons/collections4/functors/InstantiateTransformer.java
@@ -35,7 +35,8 @@ public class InstantiateTransformer<T> implements Transformer<Class<? extends T>
     private static final long serialVersionUID = 3786388740793356347L;
 
     /** Singleton instance that uses the no arg constructor */
-    public static final Transformer<Class<?>, ?> NO_ARG_INSTANCE = new InstantiateTransformer<Object>();
+    @SuppressWarnings("rawtypes")
+    private static final Transformer NO_ARG_INSTANCE = new InstantiateTransformer<Object>();
 
     /** The constructor parameter types */
     private final Class<?>[] iParamTypes;
@@ -48,8 +49,9 @@ public class InstantiateTransformer<T> implements Transformer<Class<? extends T>
      * @param <T>  the type of the objects to be created
      * @return Transformer<Class<? extends T>, T>
      */
+    @SuppressWarnings("unchecked")
     public static <T> Transformer<Class<? extends T>, T> instantiateTransformer() {
-        return new InstantiateTransformer<T>();
+        return (Transformer<Class<? extends T>, T>) NO_ARG_INSTANCE;
     }
 
     /**
diff --git a/src/main/java/org/apache/commons/collections4/functors/NOPClosure.java b/src/main/java/org/apache/commons/collections4/functors/NOPClosure.java
index 5026088f5..de9447a7a 100644
--- a/src/main/java/org/apache/commons/collections4/functors/NOPClosure.java
+++ b/src/main/java/org/apache/commons/collections4/functors/NOPClosure.java
@@ -32,7 +32,8 @@ public final class NOPClosure<E> implements Closure<E>, Serializable {
     private static final long serialVersionUID = 3518477308466486130L;
 
     /** Singleton predicate instance */
-    public static final Closure<Object> INSTANCE = new NOPClosure<Object>();
+    @SuppressWarnings("rawtypes")
+    public static final Closure INSTANCE = new NOPClosure<Object>();
 
     /**
      * Factory returning the singleton instance.
diff --git a/src/main/java/org/apache/commons/collections4/functors/NOPTransformer.java b/src/main/java/org/apache/commons/collections4/functors/NOPTransformer.java
index f530c3f5b..3d831eb29 100644
--- a/src/main/java/org/apache/commons/collections4/functors/NOPTransformer.java
+++ b/src/main/java/org/apache/commons/collections4/functors/NOPTransformer.java
@@ -32,7 +32,8 @@ public class NOPTransformer<T> implements Transformer<T, T>, Serializable {
     private static final long serialVersionUID = 2133891748318574490L;
 
     /** Singleton predicate instance */
-    public static final Transformer<Object, Object> INSTANCE = new NOPTransformer<Object>();
+    @SuppressWarnings("rawtypes")
+    public static final Transformer INSTANCE = new NOPTransformer<Object>();
 
     /**
      * Factory returning the singleton instance.
diff --git a/src/main/java/org/apache/commons/collections4/functors/NotNullPredicate.java b/src/main/java/org/apache/commons/collections4/functors/NotNullPredicate.java
index f7a1d5214..5697cfbf4 100644
--- a/src/main/java/org/apache/commons/collections4/functors/NotNullPredicate.java
+++ b/src/main/java/org/apache/commons/collections4/functors/NotNullPredicate.java
@@ -32,7 +32,8 @@ public final class NotNullPredicate<T> implements Predicate<T>, Serializable {
     private static final long serialVersionUID = 7533784454832764388L;
 
     /** Singleton predicate instance */
-    public static final Predicate<Object> INSTANCE = new NotNullPredicate<Object>();
+    @SuppressWarnings("rawtypes")
+    public static final Predicate INSTANCE = new NotNullPredicate<Object>();
 
     /**
      * Factory returning the singleton instance.
diff --git a/src/main/java/org/apache/commons/collections4/functors/NullPredicate.java b/src/main/java/org/apache/commons/collections4/functors/NullPredicate.java
index 3609a0faf..097b4312a 100644
--- a/src/main/java/org/apache/commons/collections4/functors/NullPredicate.java
+++ b/src/main/java/org/apache/commons/collections4/functors/NullPredicate.java
@@ -32,7 +32,8 @@ public final class NullPredicate<T> implements Predicate<T>, Serializable {
     private static final long serialVersionUID = 7533784454832764388L;
 
     /** Singleton predicate instance */
-    public static final Predicate<?> INSTANCE = new NullPredicate<Object>();
+    @SuppressWarnings("rawtypes")
+    public static final Predicate INSTANCE = new NullPredicate<Object>();
 
     /**
      * Factory returning the singleton instance.
diff --git a/src/main/java/org/apache/commons/collections4/functors/TruePredicate.java b/src/main/java/org/apache/commons/collections4/functors/TruePredicate.java
index 466dcd03b..61b6563da 100644
--- a/src/main/java/org/apache/commons/collections4/functors/TruePredicate.java
+++ b/src/main/java/org/apache/commons/collections4/functors/TruePredicate.java
@@ -32,7 +32,8 @@ public final class TruePredicate<T> implements Predicate<T>, Serializable {
     private static final long serialVersionUID = 3374767158756189740L;
 
     /** Singleton predicate instance */
-    public static final Predicate<?> INSTANCE = new TruePredicate<Object>();
+    @SuppressWarnings("rawtypes")
+    public static final Predicate INSTANCE = new TruePredicate<Object>();
 
     /**
      * Factory returning the singleton instance.