diff --git a/src/main/java/ch/jalu/injector/InjectionHelper.java b/src/main/java/ch/jalu/injector/InjectionHelper.java
index 123c773..7a0aaa2 100644
--- a/src/main/java/ch/jalu/injector/InjectionHelper.java
+++ b/src/main/java/ch/jalu/injector/InjectionHelper.java
@@ -6,6 +6,7 @@
 import ch.jalu.injector.instantiation.Instantiation;
 import ch.jalu.injector.instantiation.InstantiationFallback;
 
+import javax.annotation.Nullable;
 import javax.annotation.PostConstruct;
 import javax.inject.Provider;
 import java.lang.reflect.Method;
@@ -26,6 +27,7 @@ private InjectionHelper() {
      * @param <T> the class' type
      * @return injection of the class or null if none detected
      */
+    @Nullable
     public static <T> Instantiation<T> getInjection(Class<T> clazz) {
         return firstNotNull(
             ConstructorInjection.provide(clazz),
@@ -39,6 +41,7 @@ public static <T> Instantiation<T> getInjection(Class<T> clazz) {
      * @param clazz the class to search
      * @return post construct method, or null
      */
+    @Nullable
     public static Method getAndValidatePostConstructMethod(Class<?> clazz) {
         Method postConstructMethod = null;
         for (Method method : clazz.getDeclaredMethods()) {
diff --git a/src/main/java/ch/jalu/injector/InjectorImpl.java b/src/main/java/ch/jalu/injector/InjectorImpl.java
index 9abe4ad..a8b2edd 100644
--- a/src/main/java/ch/jalu/injector/InjectorImpl.java
+++ b/src/main/java/ch/jalu/injector/InjectorImpl.java
@@ -215,7 +215,9 @@ private void validatePackage(Class<?> clazz) {
      */
     private static void executePostConstructMethod(Object object) {
         Method postConstructMethod = InjectionHelper.getAndValidatePostConstructMethod(object.getClass());
-        ReflectionUtils.invokeMethod(postConstructMethod, object);
+        if (postConstructMethod != null) {
+            ReflectionUtils.invokeMethod(postConstructMethod, object);
+        }
     }
 
     private static void validateInstantiable(Class<?> clazz) {
diff --git a/src/test/java/ch/jalu/injector/InjectorImplTest.java b/src/test/java/ch/jalu/injector/InjectorImplTest.java
index 9580e41..13267a4 100644
--- a/src/test/java/ch/jalu/injector/InjectorImplTest.java
+++ b/src/test/java/ch/jalu/injector/InjectorImplTest.java
@@ -204,7 +204,7 @@ public void shouldThrowForStaticPostConstructMethod() {
     @Test
     public void shouldForwardExceptionFromPostConstruct() {
         // given / when / then
-        expectInjectorException("Error executing @PostConstruct method");
+        expectInjectorException("Could not invoke method");
         injector.getSingleton(InvalidPostConstruct.ThrowsException.class);
     }