diff --git a/.gitignore b/.gitignore
index dfcfd56..1623ab0 100644
--- a/.gitignore
+++ b/.gitignore
@@ -348,3 +348,4 @@ MigrationBackup/
 
 # Ionide (cross platform F# VS Code tools) working folder
 .ionide/
+.idea/
\ No newline at end of file
diff --git a/ApiManagementSchemaImport/Microsoft.Azure.ApiManagement.WsdlProcessor.Common/WsdlDocument.cs b/ApiManagementSchemaImport/Microsoft.Azure.ApiManagement.WsdlProcessor.Common/WsdlDocument.cs
index 1c6e39c..79c9325 100644
--- a/ApiManagementSchemaImport/Microsoft.Azure.ApiManagement.WsdlProcessor.Common/WsdlDocument.cs
+++ b/ApiManagementSchemaImport/Microsoft.Azure.ApiManagement.WsdlProcessor.Common/WsdlDocument.cs
@@ -518,41 +518,49 @@ private static void AddXmlnsAndChangePrefixReferenced(
             IEnumerable<XElement> newElements,
             Dictionary<string, string> namespaces)
         {
+            // Capture all declared xmlns attributes
             var parentNamespaces = documentElement
-            .Attributes()
-            .Where(a => a.ToString()
-            .Contains("xmlns:"))
-            .Select(a => new
-            {
-                Prefix = a.Name.LocalName,
-                Namespace = a.Value
-            }).ToDictionary(a => a.Namespace, a => a.Prefix);
+                .Attributes()
+                .Where(a => a.IsNamespaceDeclaration)
+                .Select(a => new { Prefix = a.Name.LocalName, Namespace = a.Value })
+                .ToDictionary(a => a.Namespace + "_" + a.Prefix, a => a.Prefix); // composite key
 
             foreach (var item in namespaces)
             {
-                //string prefix = string.Empty;
-                parentNamespaces.TryGetValue(item.Key, out string prefix);
-
-                if (prefix == null)
+                string desiredPrefix = item.Value;
+                string prefix = null;
+                var attr = documentElement.Attribute(XNamespace.Xmlns + desiredPrefix);
+                if (attr != null)
                 {
-                    prefix = GenerateNewNamespace(documentElement, parentNamespaces, item);
+                    if (attr.Value == item.Key)
+                    {
+                        prefix = desiredPrefix;
+                    }
+                    else
+                    {
+                        prefix = GenerateNewNamespace(documentElement, parentNamespaces, item);
+                    }
+                }
+                else
+                {
+                    documentElement.Add(new XAttribute(XNamespace.Xmlns + desiredPrefix, item.Key));
+                    parentNamespaces.Add(item.Key + "_" + desiredPrefix, desiredPrefix);
+                    prefix = desiredPrefix;
                 }
 
-                //Modify attributes from elements with the same prefix
+                // Modify attributes from elements that reference the old prefix
                 var prefixValue = item.Value + ":";
-
                 foreach (var element in newElements.DescendantsAndSelf())
                 {
-                    //Go through all attributes and modify if they have the prefix
+                    // Go through all attributes and modify if they have the prefix
                     var attributes = element
-                    .Attributes()
-                    .Where(e => e.Value.Contains(prefixValue));
-
+                        .Attributes()
+                        .Where(e => e.Value.Contains(prefixValue));
                     foreach (var attribute in attributes)
                     {
                         if (attribute.Value.Count(i => i == ':') == 1
-                        && !(Uri.TryCreate(attribute.Value, UriKind.Absolute, out var uriResult)
-                        && (uriResult.Scheme == Uri.UriSchemeHttp || uriResult.Scheme == Uri.UriSchemeHttps)))
+                            && !(Uri.TryCreate(attribute.Value, UriKind.Absolute, out var uriResult)
+                                 && (uriResult.Scheme == Uri.UriSchemeHttp || uriResult.Scheme == Uri.UriSchemeHttps)))
                         {
                             var splitValue = attribute.Value.Split(':');
                             attribute.Value = prefix + ":" + splitValue[1];
diff --git a/examples/includeExample/additional.xsd b/examples/includeExample/additional.xsd
new file mode 100644
index 0000000..a324428
--- /dev/null
+++ b/examples/includeExample/additional.xsd
@@ -0,0 +1,5 @@
+<xsd:schema xmlns:xsd="http://www.w3.org/2001/XMLSchema"
+            xmlns:tns="http://example.com/additional"
+            targetNamespace="http://example.com/additional">
+    <xsd:element name="AdditionalElement" type="xsd:string"/>
+</xsd:schema>
diff --git a/examples/includeExample/common.xsd b/examples/includeExample/common.xsd
new file mode 100644
index 0000000..83aace1
--- /dev/null
+++ b/examples/includeExample/common.xsd
@@ -0,0 +1,5 @@
+<xsd:schema xmlns:xsd="http://www.w3.org/2001/XMLSchema"
+            xmlns:tns="http://example.com/common"
+            targetNamespace="http://example.com/common">
+    <xsd:element name="CommonElement" type="xsd:string"/>
+</xsd:schema>
diff --git a/examples/includeExample/example.wsdl b/examples/includeExample/example.wsdl
new file mode 100644
index 0000000..ae42a9e
--- /dev/null
+++ b/examples/includeExample/example.wsdl
@@ -0,0 +1,41 @@
+<definitions xmlns="http://schemas.xmlsoap.org/wsdl/"
+             xmlns:tns="http://example.com/wsdl"
+             xmlns:xsd="http://www.w3.org/2001/XMLSchema"
+	     xmlns:soap="http://schemas.xmlsoap.org/wsdl/soap/"	
+             targetNamespace="http://example.com/wsdl">
+    <types>
+        <xsd:schema>
+            <xsd:import namespace="http://example.com/schema1" schemaLocation="schema1.xsd"/>
+            <xsd:import namespace="http://example.com/schema2" schemaLocation="schema2.xsd"/>
+        </xsd:schema>
+    </types>
+    <message name="ExampleRequest">
+        <part name="parameters" element="tns:ExampleElement"/>
+    </message>
+    <message name="ExampleResponse">
+        <part name="parameters" element="tns:ExampleElement"/>
+    </message>
+    <portType name="ExamplePortType">
+        <operation name="ExampleOperation">
+            <input message="tns:ExampleRequest"/>
+            <output message="tns:ExampleResponse"/>
+        </operation>
+    </portType>
+    <binding name="ExampleBinding" type="tns:ExamplePortType">
+        <soap:binding style="document" transport="http://schemas.xmlsoap.org/soap/http"/>
+        <operation name="ExampleOperation">
+            <soap:operation soapAction="http://example.com/ExampleOperation"/>
+            <input>
+                <soap:body use="literal"/>
+            </input>
+            <output>
+                <soap:body use="literal"/>
+            </output>
+        </operation>
+    </binding>
+    <service name="ExampleService">
+        <port name="ExamplePort" binding="tns:ExampleBinding">
+            <soap:address location="http://example.com/ExampleService"/>
+        </port>
+    </service>
+</definitions>
diff --git a/examples/includeExample/schema1.xsd b/examples/includeExample/schema1.xsd
new file mode 100644
index 0000000..a8caceb
--- /dev/null
+++ b/examples/includeExample/schema1.xsd
@@ -0,0 +1,11 @@
+<xsd:schema xmlns:xsd="http://www.w3.org/2001/XMLSchema"
+            xmlns:tns="http://example.com/schema1"
+            targetNamespace="http://example.com/schema1">
+    <xsd:import namespace="http://example.com/common" schemaLocation="common.xsd"/>
+    <xsd:element name="ExampleElement" type="tns:ExampleType"/>
+    <xsd:complexType name="ExampleType">
+        <xsd:sequence>
+            <xsd:element name="exampleField" type="xsd:string"/>
+        </xsd:sequence>
+    </xsd:complexType>
+</xsd:schema>
diff --git a/examples/includeExample/schema2.xsd b/examples/includeExample/schema2.xsd
new file mode 100644
index 0000000..3b871c4
--- /dev/null
+++ b/examples/includeExample/schema2.xsd
@@ -0,0 +1,12 @@
+<xsd:schema xmlns:xsd="http://www.w3.org/2001/XMLSchema"
+            xmlns:tns="http://example.com/schema2"
+            targetNamespace="http://example.com/schema2">
+    <xsd:import namespace="http://example.com/common" schemaLocation="common.xsd"/>
+    <xsd:include schemaLocation="additional.xsd"/>
+    <xsd:element name="ExampleElement" type="tns:ExampleType"/>
+    <xsd:complexType name="ExampleType">
+        <xsd:sequence>
+            <xsd:element name="exampleField" type="xsd:string"/>
+        </xsd:sequence>
+    </xsd:complexType>
+</xsd:schema>