diff --git a/xmlschema-walker/src/main/java/org/apache/ws/commons/schema/walker/XmlSchemaScope.java b/xmlschema-walker/src/main/java/org/apache/ws/commons/schema/walker/XmlSchemaScope.java
index 475f5aab..7e2c7449 100644
--- a/xmlschema-walker/src/main/java/org/apache/ws/commons/schema/walker/XmlSchemaScope.java
+++ b/xmlschema-walker/src/main/java/org/apache/ws/commons/schema/walker/XmlSchemaScope.java
@@ -352,7 +352,15 @@ private void walk(boolean isMixed, XmlSchemaContent content) {
             } else {
                 XmlSchemaSequence seq = new XmlSchemaSequence();
                 seq.getItems().add((XmlSchemaSequenceMember)baseParticle);
-                seq.getItems().add((XmlSchemaSequenceMember)ext.getParticle());
+                // we cannot cast a SchemaAll instance to SequenceMember
+                if (ext.getParticle() instanceof XmlSchemaAll) {
+                    XmlSchemaAll all = (XmlSchemaAll) ext.getParticle();
+                    for (XmlSchemaAllMember allMember : all.getItems()) {
+                        seq.getItems().add((XmlSchemaSequenceMember) allMember);
+                    }
+                } else {
+                    seq.getItems().add((XmlSchemaSequenceMember) ext.getParticle());
+                }
                 child = seq;
             }
 
diff --git a/xmlschema-walker/src/main/java/org/apache/ws/commons/schema/walker/XmlSchemaWalker.java b/xmlschema-walker/src/main/java/org/apache/ws/commons/schema/walker/XmlSchemaWalker.java
index 4c978502..4b8e6e31 100644
--- a/xmlschema-walker/src/main/java/org/apache/ws/commons/schema/walker/XmlSchemaWalker.java
+++ b/xmlschema-walker/src/main/java/org/apache/ws/commons/schema/walker/XmlSchemaWalker.java
@@ -210,13 +210,7 @@ public void walk(XmlSchemaElement element) {
             element.setMaxOccurs(XmlSchemaParticle.DEFAULT_MAX_OCCURS);
         }
 
-        XmlSchemaType schemaType = element.getSchemaType();
-        if (schemaType == null) {
-            final QName typeQName = element.getSchemaTypeName();
-            if (typeQName != null) {
-                schemaType = schemasByNamespace.getTypeByName(typeQName);
-            }
-        }
+        XmlSchemaType schemaType = getSchemaTypeOfElement(element);
 
         if (schemaType != null) {
             XmlSchemaScope scope = null;
@@ -582,4 +576,21 @@ private static QName getElementQName(XmlSchemaElement element) {
             return element.getQName();
         }
     }
+
+
+    private XmlSchemaType getSchemaTypeOfElement(XmlSchemaElement element) {
+        XmlSchemaType schemaType = element.getSchemaType();
+        if (schemaType == null) {
+            final QName typeQName = element.getSchemaTypeName();
+            if (typeQName != null) {
+                schemaType = schemasByNamespace.getTypeByName(typeQName);
+            } else {
+                final QName substitutionGroupQName = element.getSubstitutionGroup();
+                if (substitutionGroupQName != null) {
+                    schemaType = getSchemaTypeOfElement(schemasByNamespace.getElementByName(substitutionGroupQName));
+                }
+            }
+        }
+        return schemaType;
+    }
 }