diff --git a/python/src/com/jetbrains/python/psi/types/PyTypeChecker.java b/python/src/com/jetbrains/python/psi/types/PyTypeChecker.java
index 9f85131a8da5..5ac746146a46 100644
--- a/python/src/com/jetbrains/python/psi/types/PyTypeChecker.java
+++ b/python/src/com/jetbrains/python/psi/types/PyTypeChecker.java
@@ -754,13 +754,21 @@ public class PyTypeChecker {
       for (PyClassType type : toPossibleClassTypes(qualifierType)) {
         for (PyTypeProvider provider : Extensions.getExtensions(PyTypeProvider.EP_NAME)) {
           final PyType genericType = provider.getGenericType(type.getPyClass(), context);
+          final Set<PyGenericType> providedTypeGenerics = new LinkedHashSet<>();
+
           if (genericType != null) {
             match(genericType, type, context, substitutions);
+            collectGenerics(genericType, context, providedTypeGenerics, new HashSet<>());
           }
+
           for (Map.Entry<PyType, PyType> entry : provider.getGenericSubstitutions(type.getPyClass(), context).entrySet()) {
             final PyGenericType genericKey = as(entry.getKey(), PyGenericType.class);
             final PyType value = entry.getValue();
-            if (genericKey != null && value != null && !substitutions.containsKey(genericKey)) {
+
+            if (genericKey != null &&
+                value != null &&
+                !substitutions.containsKey(genericKey) &&
+                !providedTypeGenerics.contains(genericKey)) {
               substitutions.put(genericKey, value);
             }
           }
diff --git a/python/testSrc/com/jetbrains/python/Py3TypeTest.java b/python/testSrc/com/jetbrains/python/Py3TypeTest.java
index b121ef99669a..67361ae53ea8 100644
--- a/python/testSrc/com/jetbrains/python/Py3TypeTest.java
+++ b/python/testSrc/com/jetbrains/python/Py3TypeTest.java
@@ -953,6 +953,27 @@ public class Py3TypeTest extends PyTestCase {
     );
   }
 
+  // PY-27783
+  public void testApplyingSuperSubstituionToGenericClass() {
+    runWithLanguageLevel(
+      LanguageLevel.PYTHON36,
+      () -> doTest("Dict[T, int]",
+                   "from typing import TypeVar, Generic, Dict, List\n" +
+                   "\n" +
+                   "T = TypeVar('T')\n" +
+                   "\n" +
+                   "class A(Generic[T]):\n" +
+                   "    pass\n" +
+                   "\n" +
+                   "class B(A[List[T]], Generic[T]):\n" +
+                   "    def __init__(self) -> None:\n" +
+                   "        self.value_set: Dict[T, int] = {}\n" +
+                   "\n" +
+                   "    def foo(self) -> None:\n" +
+                   "        expr = self.value_set")
+    );
+  }
+
   private void doTest(final String expectedType, final String text) {
     myFixture.configureByText(PythonFileType.INSTANCE, text);
     final PyExpression expr = myFixture.findElementByText("expr", PyExpression.class);