diff --git a/java/com.sap.sse.security.persistence.test/src/com/sap/sse/security/persistence/test/SessionPersistenceTest.java b/java/com.sap.sse.security.persistence.test/src/com/sap/sse/security/persistence/test/SessionPersistenceTest.java
index a632cd2f27a..80459559735 100755
--- a/java/com.sap.sse.security.persistence.test/src/com/sap/sse/security/persistence/test/SessionPersistenceTest.java
+++ b/java/com.sap.sse.security.persistence.test/src/com/sap/sse/security/persistence/test/SessionPersistenceTest.java
@@ -45,11 +45,11 @@ public class SessionPersistenceTest {
         final String attr2Key = "a2";
         final boolean attr2Value = true;
         final String realm1Name = "realm1";
-        final String realm1Principal1Name = "r1p1";
-        final String realm1Principal2Name = "r1p2";
+        final String realm1Principal1Name = "r1.p1";
+        final String realm1Principal2Name = "r1/\",,p2";
         final String realm2Name = "realm2";
-        final String realm2Principal1Name = "r2p1";
-        final String realm2Principal2Name = "r2p2";
+        final String realm2Principal1Name = "r2\\p1";
+        final String realm2Principal2Name = "r2.'_p2";
         final String principalAttribute = "org.apache.shiro.subject.support.DefaultSubjectContext_PRINCIPALS_SESSION_KEY";
         final SimplePrincipalCollection principalCollection = new SimplePrincipalCollection();
         principalCollection.add(realm1Principal1Name, realm1Name);
diff --git a/java/com.sap.sse.security.persistence/src/com/sap/sse/security/persistence/impl/DomainObjectFactoryImpl.java b/java/com.sap.sse.security.persistence/src/com/sap/sse/security/persistence/impl/DomainObjectFactoryImpl.java
index 408fe43be4b..e4806724e46 100755
--- a/java/com.sap.sse.security.persistence/src/com/sap/sse/security/persistence/impl/DomainObjectFactoryImpl.java
+++ b/java/com.sap.sse.security.persistence/src/com/sap/sse/security/persistence/impl/DomainObjectFactoryImpl.java
@@ -61,9 +61,12 @@ public class DomainObjectFactoryImpl implements DomainObjectFactory {
             final Iterable<Document> sessionAttributes = sessionDocument.get(FieldNames.SESSION_ATTRIBUTES.name(), Iterable.class);
             for (final Document sessionAttributeDocument : sessionAttributes) {
                 final Object value = sessionAttributeDocument.get(FieldNames.SESSION_ATTRIBUTE_VALUE.name());
-                if (value instanceof Document) { // assume this encodes a PrincipalCollection
+                if (value instanceof Iterable<?>) { // assume this encodes a PrincipalCollection in the form of a list of Document objects with
+                    // a realm name and a principal list, each:
                     SimplePrincipalCollection principalCollection = new SimplePrincipalCollection();
-                    ((Document) value).forEach((realmName, principalList)->{
+                    ((Iterable<?>) value).forEach(realmDocument->{
+                        final String realmName = ((Document) realmDocument).getString(FieldNames.SESSION_PRINCIPAL_REALM_NAME.name());
+                        final Iterable<?> principalList = (Iterable<?>) ((Document) realmDocument).get(FieldNames.SESSION_PRINCIPAL_REALM_VALUE.name());
                         for (final Object principal : (Iterable<?>) principalList) {
                             principalCollection.add(principal, realmName);
                         }
diff --git a/java/com.sap.sse.security.persistence/src/com/sap/sse/security/persistence/impl/FieldNames.java b/java/com.sap.sse.security.persistence/src/com/sap/sse/security/persistence/impl/FieldNames.java
index c8ec7e42681..5e20eb00cd1 100755
--- a/java/com.sap.sse.security.persistence/src/com/sap/sse/security/persistence/impl/FieldNames.java
+++ b/java/com.sap.sse.security.persistence/src/com/sap/sse/security/persistence/impl/FieldNames.java
@@ -4,5 +4,6 @@ public enum FieldNames {
     CACHE_NAME,
     
     SESSION_ID, SESSION_HOST, SESSION_LAST_ACCESS_TIME, SESSION_START_TIMESTAMP, SESSION_TIMEOUT,
-    SESSION_ATTRIBUTES, SESSION_ATTRIBUTE_NAME, SESSION_ATTRIBUTE_VALUE;
+    SESSION_ATTRIBUTES, SESSION_ATTRIBUTE_NAME, SESSION_ATTRIBUTE_VALUE, SESSION_PRINCIPAL_REALM_NAME,
+    SESSION_PRINCIPAL_REALM_VALUE;
 }
diff --git a/java/com.sap.sse.security.persistence/src/com/sap/sse/security/persistence/impl/MongoObjectFactoryImpl.java b/java/com.sap.sse.security.persistence/src/com/sap/sse/security/persistence/impl/MongoObjectFactoryImpl.java
index e88644c900a..c9c4b86573d 100755
--- a/java/com.sap.sse.security.persistence/src/com/sap/sse/security/persistence/impl/MongoObjectFactoryImpl.java
+++ b/java/com.sap.sse.security.persistence/src/com/sap/sse/security/persistence/impl/MongoObjectFactoryImpl.java
@@ -69,14 +69,17 @@ public class MongoObjectFactoryImpl implements MongoObjectFactory {
         sessionCollection.replaceOne(key, sessionAsDocument, new UpdateOptions().upsert(true));
     }
     
-    private Document storePrincipalCollection(PrincipalCollection principalCollection) {
-        final Document result = new Document();
+    private List<Document> storePrincipalCollection(PrincipalCollection principalCollection) {
+        final List<Document> result = new ArrayList<>();
         for (final String realmName : principalCollection.getRealmNames()) {
             final List<String> principalNames = new ArrayList<>();
             for (Object o : principalCollection.fromRealm(realmName)) {
                 principalNames.add(o.toString());
             }
-            result.append(realmName, principalNames);
+            final Document realmDocument = new Document().
+                    append(FieldNames.SESSION_PRINCIPAL_REALM_NAME.name(), realmName).
+                    append(FieldNames.SESSION_PRINCIPAL_REALM_VALUE.name(), principalNames);
+            result.add(realmDocument);
         }
         return result;
     }