diff --git a/SitecorePackageDeployer/Tasks/InstallPackage.cs b/SitecorePackageDeployer/Tasks/InstallPackage.cs
index 1492dce..7403a16 100644
--- a/SitecorePackageDeployer/Tasks/InstallPackage.cs
+++ b/SitecorePackageDeployer/Tasks/InstallPackage.cs
@@ -478,7 +478,30 @@ private void SaveInstallationMessages(string installationHistoryRoot, List<Conti
                 using (FileStream fileStream = File.Create(messagesFile))
                 {
                     XmlEntrySerializer xmlEntrySerializer = new XmlEntrySerializer();
-                    xmlEntrySerializer.Serialize(logMessages, fileStream);
+
+                    //For some reason, this has changed in Sitecore 9. We are using reflection to get it because the fileStream parameter can be a FileStream or Stream
+                    //xmlEntrySerializer.Serialize(logMessages, fileStream);
+                    Type serializerType = xmlEntrySerializer.GetType();
+
+                    MethodInfo serializeMethod = serializerType.GetMethod("Serialize",
+                        BindingFlags.Public | BindingFlags.Instance,
+                        null,
+                        new Type[] { logMessages.GetType(), typeof(FileStream) },
+                        null);
+
+                    if (serializeMethod == null)
+                    {
+                        serializeMethod = serializerType.GetMethod("Serialize",
+                        BindingFlags.Public | BindingFlags.Instance,
+                        null,
+                        new Type[] { logMessages.GetType(), typeof(Stream) },
+                        null);
+                    }
+
+                    if (serializeMethod != null)
+                    {
+                        serializeMethod.Invoke(xmlEntrySerializer, new object[] { logMessages, fileStream });
+                    }
                 }
             }
             catch (Exception ex)