diff --git a/sramongo/mongo_schema.py b/sramongo/mongo_schema.py
index <HASH>..<HASH> 100644
--- a/sramongo/mongo_schema.py
+++ b/sramongo/mongo_schema.py
@@ -414,6 +414,8 @@ class Sample(Document):
     ddbj_links = ListField(EmbeddedDocumentField(DDBJLink), default=list)
     ena_links = ListField(EmbeddedDocumentField(ENALink), default=list)
 
+    meta = {'allow_inheritance': True}
+
     def __str__(self):
         return DocumentString(self).string
 
@@ -509,6 +511,8 @@ class Experiment(Document):
     db_flags = ListField(StringField(), default=list)
     pipeline_flags = ListField(StringField(), default=list)
 
+    meta = {'allow_inheritance': True}
+
     def __str__(self):
         return DocumentString(self).string
 
@@ -629,6 +633,8 @@ class Run(Document):
     db_created = DateTimeField(default=datetime.datetime.now)
     db_modified = DateTimeField()
 
+    meta = {'allow_inheritance': True}
+
     def __str__(self):
         return DocumentString(self).string
Adds inheritance to Sample, Experiment, and Run.