diff --git a/changelog.md b/changelog.md
index cc16542..3bc5108 100644
--- a/changelog.md
+++ b/changelog.md
@@ -1,3 +1,6 @@
+### 1.3.2
+ * Fixes compatibility of Schemas with tables from different dynamodm module instances.
+
 ### 1.3.1
  * Fixes removal of unversioned documents via a versioned model.
 
diff --git a/lib/shared.js b/lib/shared.js
index 2969fa9..76f78dd 100644
--- a/lib/shared.js
+++ b/lib/shared.js
@@ -3,8 +3,8 @@
 const Ajv = require('ajv');
 
 // internal types for AJV
-const kExtendedTypeDate = Symbol('extendedType:date');
-const kExtendedTypeBuffer = Symbol('extendedType:buffer');
+const kExtendedTypeDate = Symbol.for('dynamodm:extendedType:date');
+const kExtendedTypeBuffer = Symbol.for('dynamodm:extendedType:buffer');
 
 // this AJV instance is used for general validation, compiled schemas do not modify data
 const ajv = new Ajv({
@@ -118,19 +118,19 @@ unMarshallingAjv.addKeyword({
     }
 });
 
-const kModelTable = Symbol();
-const kModelSchema = Symbol();
-const kModelLogger = Symbol();
-const kTableIsReady = Symbol();
-const kTableDDBClient = Symbol();
-const kTableIndices = Symbol();
-const kTableGetBackoffDelayMs = Symbol();
-const kSchemaCompiled = Symbol('schema:compiled');
-const kSchemaMarshall = Symbol('schema:marshall');
-const kSchemaUnMarshall = Symbol('schema:unmarshall');
-const kSchemaIndices = Symbol('schema:indices');
-const kSchemaNewId = Symbol('schema:newId');
-const kOptionSkipValidation = Symbol();
+const kModelTable = Symbol.for('dynamodm:model:table');
+const kModelSchema = Symbol.for('dynamodm:model:schema');
+const kModelLogger = Symbol.for('dynamodm:model:logger');
+const kTableIsReady = Symbol.for('dynamodm:table:ready');
+const kTableDDBClient = Symbol.for('dynamodm:table:ddbc');
+const kTableIndices = Symbol.for('dynamodm:table:indices');
+const kTableGetBackoffDelayMs = Symbol.for('dynamodm:table:gbdms');
+const kSchemaCompiled = Symbol.for('dynamodm:schema:compiled');
+const kSchemaMarshall = Symbol.for('dynamodm:schema:marshall');
+const kSchemaUnMarshall = Symbol.for('dynamodm:schema:unmarshall');
+const kSchemaIndices = Symbol.for('dynamodm:schema:indices');
+const kSchemaNewId = Symbol.for('dynamodm:schema:newId');
+const kOptionSkipValidation = Symbol.for('dynamodm:option:skipValidate');
 
 // Built-in schema types
 const DocId = { type:'string', minLength:1, maxLength:1024 };
diff --git a/lib/table.js b/lib/table.js
index 1df7d38..483bde4 100644
--- a/lib/table.js
+++ b/lib/table.js
@@ -2,7 +2,6 @@
 const { DynamoDBClient, CreateTableCommand, DescribeTableCommand, UpdateTableCommand, DeleteTableCommand } = require('@aws-sdk/client-dynamodb');
 const { DynamoDBDocumentClient } = require('@aws-sdk/lib-dynamodb');
 
-const { Schema } = require('./schema');
 const { createModel } = require('./model');
 const {
     kTableIsReady,
@@ -110,8 +109,8 @@ class Table {
             }));
         } catch (err) {
             // ResourceInUseException is only thrown if the table already exists
+            /* c8 ignore next 3 */
             if (err.name !== 'ResourceInUseException') {
-                /* c8 ignore next 2 */
                 throw err;
             }
         }
@@ -129,8 +128,8 @@ class Table {
             } else if (response.Table.TableStatus === 'ACTIVE' || response.Table.TableStatus === 'UPDATING') {
                 this.#logger.info('Table %s now %s', this.name, response.Table.TableStatus);
                 created = true;
+                /* c8 ignore next 3 */
             } else {
-                /* c8 ignore next 2 */
                 throw new Error(`Table ${this.name} status is ${response.Table.TableStatus}.`);
             }
 
@@ -194,7 +193,9 @@ class Table {
     }
 
     model(schema){
-        if (!(schema instanceof Schema)) {
+        // Not checking using 'instanceof' here, because the Schema might come
+        // from a different realm, and we want to allow that.
+        if (!(schema && schema.name && schema.idFieldName && schema.source && schema.methods)) {
             throw new Error('The model schema must be a valid DynamoDM.Schema().');
         }
         // add the schema to the table's schema list and return a corresponding
diff --git a/test/multi.js b/test/multi.js
new file mode 100644
index 0000000..f26af1b
--- /dev/null
+++ b/test/multi.js
@@ -0,0 +1,79 @@
+const t = require('tap');
+
+const clientOptions = {
+    endpoint: 'http://localhost:8000'
+};
+
+// get two unique instances by clearing the require cache:
+const DynamoDMConstructor1 = require('../');
+for (const k in require.cache) {
+    delete require.cache[k];
+}
+const DynamoDMConstructor2 = require('../');
+
+const DynamoDM1 = DynamoDMConstructor1({clientOptions, logger:{level:'error'}});
+const DynamoDM2 = DynamoDMConstructor2({clientOptions, logger:{level:'error'}});
+
+t.test('unique identity', async t => {
+    t.ok(DynamoDMConstructor1 !== DynamoDMConstructor2, "check that we've created separate module instances for testing");
+    t.notOk(DynamoDM1.Schema('test') instanceof DynamoDM2.Schema('test').constructor, 'check that Schema types are unique');
+});
+
+
+t.test('crud with schema from separate module', async t => {
+    const table = DynamoDM1.Table({ name: 'test-table-multi-crud'});
+    const ThingSchema = DynamoDM2.Schema('namespace.thing', {
+        properties: {
+            id:           DynamoDM2.DocIdField,
+            aaaa:         {type: 'string'},
+            bbbb:         {type: 'number'},
+            cccc:         {type: 'string'},
+            blob:         DynamoDM2.Binary,
+            createdAt:    DynamoDM2.CreatedAtField,
+            updatedAt:    DynamoDM2.UpdatedAtField
+        },
+        required: ['id', 'aaaa', 'bbbb'],
+        additionalProperties: false
+    });
+    const Thing = table.model(ThingSchema);
+
+    await table.ready();
+
+    let x, y;
+    await t.test('create', async t => {
+        x = new Thing({aaaa: 'a', bbbb:1, blob: Buffer.from('hello crud'), });
+        await x.save();
+
+        y = await Thing.getById(x.id);
+        t.strictSame(y, x);
+    });
+
+    await t.test('update', async t => {
+        x.bbbb = 2;
+        await x.save();
+
+        y = await Thing.getById(x.id);
+        t.strictSame(y, x);
+    });
+
+    await t.test('query', async t => {
+        const aThing = await Thing.queryOne({ type: 'namespace.thing' });
+        t.equal(aThing.constructor, (new Thing({aaaa:'a',bbbb:2})).constructor, 'should have the correct constructor');
+    });
+
+    await t.test('remove', async t => {
+        const oldId = x.id;
+        await x.remove();
+
+        t.equal(await Thing.getById(oldId), null);
+    });
+
+    t.teardown(async () => {
+        await table.deleteTable();
+        table.destroyConnection();
+    });
+
+    t.end();
+});
+
+t.end();