diff --git a/morf-postgresql/src/main/java/org/alfasoftware/morf/jdbc/postgresql/PostgreSQLMetaDataProvider.java b/morf-postgresql/src/main/java/org/alfasoftware/morf/jdbc/postgresql/PostgreSQLMetaDataProvider.java
index 1295800d7..18fe9fc6b 100644
--- a/morf-postgresql/src/main/java/org/alfasoftware/morf/jdbc/postgresql/PostgreSQLMetaDataProvider.java
+++ b/morf-postgresql/src/main/java/org/alfasoftware/morf/jdbc/postgresql/PostgreSQLMetaDataProvider.java
@@ -5,6 +5,7 @@
 import static org.alfasoftware.morf.jdbc.DatabaseMetaDataProviderUtils.shouldIgnoreIndex;
 
 import java.sql.Connection;
+import java.sql.PreparedStatement;
 import java.sql.ResultSet;
 import java.sql.SQLException;
 import java.sql.Statement;
@@ -41,9 +42,19 @@ public class PostgreSQLMetaDataProvider extends DatabaseMetaDataProvider impleme
   private static final Log log = LogFactory.getLog(PostgreSQLMetaDataProvider.class);
 
   private static final Pattern REALNAME_COMMENT_MATCHER = Pattern.compile(".*"+PostgreSQLDialect.REAL_NAME_COMMENT_LABEL+":\\[([^\\]]*)\\](/TYPE:\\[([^\\]]*)\\])?.*");
+  private static final String EXTENSION_RELATIONS_SQL = "SELECT c.relname"
+    + " FROM pg_catalog.pg_class c"
+    + " JOIN pg_catalog.pg_namespace n ON n.oid = c.relnamespace"
+    + " JOIN pg_catalog.pg_depend d ON d.classid = 'pg_catalog.pg_class'::pg_catalog.regclass"
+    + " AND d.objid = c.oid AND d.objsubid = 0"
+    + " JOIN pg_catalog.pg_extension e ON d.refclassid = 'pg_catalog.pg_extension'::pg_catalog.regclass"
+    + " AND d.refobjid = e.oid"
+    + " WHERE d.deptype = 'e'";
+  private static final String SCHEMA_EXTENSION_RELATIONS_SQL = EXTENSION_RELATIONS_SQL + " AND n.nspname = ?";
 
   private final Supplier<Map<AName, RealName>> allIndexNames = Suppliers.memoize(this::loadAllIndexNames);
   private final Supplier<Map<String, List<Index>>> allIgnoredIndexes = Suppliers.memoize(this::loadIgnoredIndexes);
+  private final Supplier<Set<AName>> extensionRelationNames = Suppliers.memoize(this::loadExtensionRelationNames);
   private final Set<RealName> allIgnoredIndexesTables = new HashSet<>();
 
   public PostgreSQLMetaDataProvider(Connection connection, String schemaName) {
@@ -57,6 +68,48 @@ protected boolean isPrimaryKeyIndex(RealName indexName) {
   }
 
 
+  @Override
+  protected boolean isSystemTable(RealName tableName) {
+    return extensionRelationNames.get().contains(tableName);
+  }
+
+
+  @Override
+  protected boolean isSystemView(RealName viewName) {
+    return extensionRelationNames.get().contains(viewName);
+  }
+
+
+  private Set<AName> loadExtensionRelationNames() {
+    try {
+      if (StringUtils.isBlank(schemaName)) {
+        try (PreparedStatement statement = connection.prepareStatement(EXTENSION_RELATIONS_SQL)) {
+          return readExtensionRelationNames(statement);
+        }
+      }
+
+      try (PreparedStatement statement = connection.prepareStatement(SCHEMA_EXTENSION_RELATIONS_SQL)) {
+        statement.setString(1, schemaName);
+        return readExtensionRelationNames(statement);
+      }
+    }
+    catch (SQLException e) {
+      throw new RuntimeSqlException(e);
+    }
+  }
+
+
+  private Set<AName> readExtensionRelationNames(PreparedStatement statement) throws SQLException {
+    Set<AName> relationNames = new HashSet<>();
+    try (ResultSet resultSet = statement.executeQuery()) {
+      while (resultSet.next()) {
+        relationNames.add(named(resultSet.getString(1)));
+      }
+    }
+    return relationNames;
+  }
+
+
   @Override
   protected DataType dataTypeFromSqlType(int sqlType, String typeName, int width) {
 
diff --git a/morf-postgresql/src/test/java/org/alfasoftware/morf/jdbc/postgresql/TestPostgreSqlMetaDataProvider.java b/morf-postgresql/src/test/java/org/alfasoftware/morf/jdbc/postgresql/TestPostgreSqlMetaDataProvider.java
index b98d3598b..1b21e2139 100644
--- a/morf-postgresql/src/test/java/org/alfasoftware/morf/jdbc/postgresql/TestPostgreSqlMetaDataProvider.java
+++ b/morf-postgresql/src/test/java/org/alfasoftware/morf/jdbc/postgresql/TestPostgreSqlMetaDataProvider.java
@@ -55,6 +55,15 @@
 public class TestPostgreSqlMetaDataProvider {
   private static final String TABLE_NAME = "AREALTABLE";
   private static final String TEST_SCHEMA = "TestSchema";
+  private static final String EXTENSION_RELATIONS_SQL = "SELECT c.relname"
+    + " FROM pg_catalog.pg_class c"
+    + " JOIN pg_catalog.pg_namespace n ON n.oid = c.relnamespace"
+    + " JOIN pg_catalog.pg_depend d ON d.classid = 'pg_catalog.pg_class'::pg_catalog.regclass"
+    + " AND d.objid = c.oid AND d.objsubid = 0"
+    + " JOIN pg_catalog.pg_extension e ON d.refclassid = 'pg_catalog.pg_extension'::pg_catalog.regclass"
+    + " AND d.refobjid = e.oid"
+    + " WHERE d.deptype = 'e'";
+  private static final String SCHEMA_EXTENSION_RELATIONS_SQL = EXTENSION_RELATIONS_SQL + " AND n.nspname = ?";
 
   private final DataSource dataSource = mock(DataSource.class, RETURNS_SMART_NULLS);
   private final Connection connection = mock(Connection.class, RETURNS_SMART_NULLS);
@@ -69,6 +78,12 @@ public void setup() {
   @Before
   public void before() throws SQLException {
     when(dataSource.getConnection()).thenReturn(connection);
+
+    PreparedStatement extensionStatement = mock(PreparedStatement.class, RETURNS_SMART_NULLS);
+    ResultSet extensionRelations = mock(ResultSet.class, RETURNS_SMART_NULLS);
+    when(connection.prepareStatement(SCHEMA_EXTENSION_RELATIONS_SQL)).thenReturn(extensionStatement);
+    when(extensionStatement.executeQuery()).thenReturn(extensionRelations);
+    when(extensionRelations.next()).thenReturn(false);
   }
 
 
@@ -95,6 +110,70 @@ public void testLoadSequences() throws SQLException {
     verify(statement).setString(1, TEST_SCHEMA);
   }
 
+
+  /**
+   * Checks that tables and views belonging to extensions are excluded from application metadata.
+   *
+   * @throws SQLException exception
+   */
+  @Test
+  public void testExtensionRelationsAreSystemRelations() throws SQLException {
+    // Given
+    PreparedStatement extensionStatement = mock(PreparedStatement.class, RETURNS_SMART_NULLS);
+    ResultSet extensionRelations = mock(ResultSet.class, RETURNS_SMART_NULLS);
+    when(connection.prepareStatement(SCHEMA_EXTENSION_RELATIONS_SQL)).thenReturn(extensionStatement);
+    when(extensionStatement.executeQuery()).thenReturn(extensionRelations);
+    when(extensionRelations.next()).thenReturn(true, true, false);
+    when(extensionRelations.getString(1)).thenReturn("extension_table", "extension_view");
+
+    DatabaseMetaData databaseMetaData = mock(DatabaseMetaData.class, RETURNS_SMART_NULLS);
+    ResultSet tables = mockRelations("extension_table", "application_table");
+    ResultSet views = mockRelations("extension_view", "application_view");
+    when(connection.getMetaData()).thenReturn(databaseMetaData);
+    when(databaseMetaData.getTables(null, TEST_SCHEMA, null, new String[] { "TABLE" }))
+      .thenReturn(tables);
+    when(databaseMetaData.getTables(null, TEST_SCHEMA, null, new String[] { "VIEW" }))
+      .thenReturn(views);
+
+    // When
+    Schema postgresMetaDataProvider = postgres.openSchema(connection, "TestDatabase", TEST_SCHEMA);
+
+    // Then
+    assertThat("Extension tables should be excluded", postgresMetaDataProvider.tableNames(), contains("application_table"));
+    assertThat("Extension views should be excluded", postgresMetaDataProvider.viewNames(), contains("application_view"));
+    verify(extensionStatement).setString(1, TEST_SCHEMA);
+    verify(extensionStatement).executeQuery();
+  }
+
+
+  /**
+   * Checks that extension relations can be loaded when no schema filter is supplied.
+   *
+   * @throws SQLException exception
+   */
+  @Test
+  public void testExtensionRelationsWithoutSchemaFilter() throws SQLException {
+    // Given
+    PreparedStatement extensionStatement = mock(PreparedStatement.class, RETURNS_SMART_NULLS);
+    ResultSet extensionRelations = mock(ResultSet.class, RETURNS_SMART_NULLS);
+    when(connection.prepareStatement(EXTENSION_RELATIONS_SQL)).thenReturn(extensionStatement);
+    when(extensionStatement.executeQuery()).thenReturn(extensionRelations);
+    when(extensionRelations.next()).thenReturn(false);
+
+    DatabaseMetaData databaseMetaData = mock(DatabaseMetaData.class, RETURNS_SMART_NULLS);
+    ResultSet tables = mockRelations("application_table_one", "application_table_two");
+    when(connection.getMetaData()).thenReturn(databaseMetaData);
+    when(databaseMetaData.getTables(null, null, null, new String[] { "TABLE" })).thenReturn(tables);
+
+    // When
+    Schema postgresMetaDataProvider = new PostgreSQLMetaDataProvider(connection, null);
+
+    // Then
+    assertThat("Application tables should be retained", postgresMetaDataProvider.tableNames(),
+      contains("application_table_one", "application_table_two"));
+    verify(extensionStatement).executeQuery();
+  }
+
   /**
    * Checks the SQL run for retrieving sequences information
    *
@@ -181,6 +260,15 @@ public void testLoadAllIgnoredIndexes() throws SQLException {
   }
 
 
+  private ResultSet mockRelations(String firstRelation, String secondRelation) throws SQLException {
+    ResultSet resultSet = mock(ResultSet.class, RETURNS_SMART_NULLS);
+    when(resultSet.next()).thenReturn(true, true, false);
+    when(resultSet.getString(2)).thenReturn(TEST_SCHEMA);
+    when(resultSet.getString(3)).thenReturn(firstRelation, firstRelation, secondRelation, secondRelation);
+    return resultSet;
+  }
+
+
   /**
    * Mockito {@link Answer} that returns a mock result set with a given number of resultRows.
    */