diff --git a/src/main/java/spoon/reflect/cu/position/NoSourcePosition.java b/src/main/java/spoon/reflect/cu/position/NoSourcePosition.java
index 9cd4a6e3efc..60226d65692 100644
--- a/src/main/java/spoon/reflect/cu/position/NoSourcePosition.java
+++ b/src/main/java/spoon/reflect/cu/position/NoSourcePosition.java
@@ -7,6 +7,7 @@
 
 import spoon.reflect.cu.CompilationUnit;
 import spoon.reflect.cu.SourcePosition;
+import spoon.support.reflect.cu.CompilationUnitImpl;
 
 import java.io.File;
 import java.io.Serializable;
@@ -23,9 +24,15 @@ public File getFile() {
 		return null;
 	}
 
+	// avoid null pointer exceptions later
+	public static class NullCompilationUnit extends CompilationUnitImpl {
+		private NullCompilationUnit() { }
+	}
+	private static final CompilationUnit instanceNullCompilationUnit = new NullCompilationUnit();
+
 	@Override
 	public CompilationUnit getCompilationUnit() {
-		return null;
+		return instanceNullCompilationUnit;
 	}
 
 	@Override
diff --git a/src/main/java/spoon/reflect/factory/CompilationUnitFactory.java b/src/main/java/spoon/reflect/factory/CompilationUnitFactory.java
index 5f03c490897..0e3c83e073f 100644
--- a/src/main/java/spoon/reflect/factory/CompilationUnitFactory.java
+++ b/src/main/java/spoon/reflect/factory/CompilationUnitFactory.java
@@ -7,6 +7,7 @@
 
 import spoon.SpoonException;
 import spoon.reflect.cu.CompilationUnit;
+import spoon.reflect.cu.position.NoSourcePosition;
 import spoon.reflect.declaration.CtModule;
 import spoon.reflect.declaration.CtPackage;
 import spoon.reflect.declaration.CtType;
@@ -49,7 +50,7 @@ public CompilationUnit create() {
 	}
 
 	public CompilationUnit getOrCreate(CtPackage ctPackage) {
-		if (ctPackage.getPosition().getCompilationUnit() != null) {
+		if (!(ctPackage.getPosition().getCompilationUnit() instanceof NoSourcePosition.NullCompilationUnit)) {
 			return ctPackage.getPosition().getCompilationUnit();
 		} else {
 
@@ -76,7 +77,7 @@ public CompilationUnit getOrCreate(CtType type) {
 		if (type == null) {
 			return null;
 		}
-		if (type.getPosition().getCompilationUnit() != null) {
+		if (!(type.getPosition().getCompilationUnit() instanceof NoSourcePosition.NullCompilationUnit)) {
 			return type.getPosition().getCompilationUnit();
 		}
 
@@ -103,7 +104,7 @@ public CompilationUnit getOrCreate(CtType type) {
 	}
 
 	public CompilationUnit getOrCreate(CtModule module) {
-		if (module.getPosition().getCompilationUnit() != null) {
+		if (!(module.getPosition().getCompilationUnit() instanceof NoSourcePosition.NullCompilationUnit)) {
 			return module.getPosition().getCompilationUnit();
 		} else {
 			File file = this.factory.getEnvironment().getOutputDestinationHandler().getOutputPath(module, null, null).toFile();
diff --git a/src/main/java/spoon/support/modelobs/SourceFragmentCreator.java b/src/main/java/spoon/support/modelobs/SourceFragmentCreator.java
index 2c9bbcfb872..4b0145e0719 100644
--- a/src/main/java/spoon/support/modelobs/SourceFragmentCreator.java
+++ b/src/main/java/spoon/support/modelobs/SourceFragmentCreator.java
@@ -6,6 +6,7 @@
 package spoon.support.modelobs;
 
 import spoon.reflect.cu.CompilationUnit;
+import spoon.reflect.cu.position.NoSourcePosition;
 import spoon.reflect.declaration.CtElement;
 import spoon.reflect.path.CtRole;
 import spoon.support.sniper.internal.ElementSourceFragment;
@@ -23,7 +24,7 @@ protected void onChange(CtElement currentElement, CtRole role) {
 			return;
 		}
 		CompilationUnit cu = currentElement.getPosition().getCompilationUnit();
-		if (cu != null) {
+		if (!(cu instanceof NoSourcePosition.NullCompilationUnit)) {
 			//getOriginalSourceFragment is not only a getter, it actually
 			//builds a tree of SourceFragments of compilation unit of the modified element
 			cu.getOriginalSourceFragment();
diff --git a/src/main/java/spoon/support/sniper/internal/ElementSourceFragment.java b/src/main/java/spoon/support/sniper/internal/ElementSourceFragment.java
index 5e650c61ea8..4f65e08acbb 100644
--- a/src/main/java/spoon/support/sniper/internal/ElementSourceFragment.java
+++ b/src/main/java/spoon/support/sniper/internal/ElementSourceFragment.java
@@ -11,6 +11,7 @@
 import spoon.reflect.cu.CompilationUnit;
 import spoon.reflect.cu.SourcePosition;
 import spoon.reflect.cu.SourcePositionHolder;
+import spoon.reflect.cu.position.NoSourcePosition;
 import spoon.reflect.declaration.CtCompilationUnit;
 import spoon.reflect.declaration.CtElement;
 import spoon.reflect.declaration.CtModifiable;
@@ -176,7 +177,7 @@ protected void exit(CtElement e) {
 	 */
 	private ElementSourceFragment addChild(ElementSourceFragment parentFragment, CtRole roleInParent, SourcePositionHolder otherElement) {
 		SourcePosition otherSourcePosition = otherElement.getPosition();
-		if (otherSourcePosition instanceof SourcePositionImpl && otherSourcePosition.getCompilationUnit() != null) {
+		if (otherSourcePosition instanceof SourcePositionImpl && !(otherSourcePosition.getCompilationUnit() instanceof NoSourcePosition.NullCompilationUnit)) {
 			if (parentFragment.isFromSameSource(otherSourcePosition)) {
 				ElementSourceFragment otherFragment = new ElementSourceFragment(otherElement, parentFragment.getRoleHandler(roleInParent, otherElement));
 				//parent and child are from the same file. So we can connect their positions into one tree