diff --git a/modules/python/src2/pycompat.hpp b/modules/python/src2/pycompat.hpp
index 03379ec956..8b44726d5f 100644
--- a/modules/python/src2/pycompat.hpp
+++ b/modules/python/src2/pycompat.hpp
@@ -231,7 +231,12 @@ PyObject* pyopencv_from(const TYPE& src)
             ERROR_HANDLER; \
         } \
         CVPY_TYPE_INCREF(pyopencv_##NAME##_TypePtr); \
-        PyModule_AddObject(m, #WNAME, (PyObject *)pyopencv_##NAME##_TypePtr); \
+        if (PyModule_AddObject(m, #WNAME, (PyObject *)pyopencv_##NAME##_TypePtr) < 0) \
+        { \
+            printf("Failed to register a new type: " #WNAME  ", base (" #BASE ")\n"); \
+            Py_DECREF(pyopencv_##NAME##_TypePtr); \
+            ERROR_HANDLER; \
+        } \
     }
 
 //==================================================================================================
@@ -304,10 +309,15 @@ PyObject* pyopencv_from(const TYPE& src)
         pyopencv_##NAME##_TypePtr = PyType_FromSpecWithBases(&pyopencv_##NAME##_Spec, bases); \
         if (!pyopencv_##NAME##_TypePtr) \
         { \
-            printf("Failed to init: " #WNAME ", base (" #BASE ")" "\n"); \
+            printf("Failed to create type from spec: " #WNAME ", base (" #BASE ")\n"); \
+            ERROR_HANDLER; \
+        } \
+        if (PyModule_AddObject(m, #WNAME, (PyObject *)pyopencv_##NAME##_TypePtr) < 0) \
+        { \
+            printf("Failed to register a new type: " #WNAME  ", base (" #BASE ")\n"); \
+            Py_DECREF(pyopencv_##NAME##_TypePtr); \
             ERROR_HANDLER; \
         } \
-        PyModule_AddObject(m, #NAME, (PyObject *)pyopencv_##NAME##_TypePtr); \
     }
 
 // Debug module load:
diff --git a/platforms/winpack_dldt/2021.4.2/20220118-dldt-fix-msvs-compilation-21469.patch b/platforms/winpack_dldt/2021.4.2/20220118-dldt-fix-msvs-compilation-21469.patch
new file mode 100644
index 0000000000..411d5cbd5c
--- /dev/null
+++ b/platforms/winpack_dldt/2021.4.2/20220118-dldt-fix-msvs-compilation-21469.patch
@@ -0,0 +1,12 @@
+diff --git a/inference-engine/src/plugin_api/caseless.hpp b/inference-engine/src/plugin_api/caseless.hpp
+index d8ce739..0dd8886 100644
+--- a/inference-engine/src/plugin_api/caseless.hpp
++++ b/inference-engine/src/plugin_api/caseless.hpp
+@@ -12,6 +12,7 @@
+ #include <algorithm>
+ #include <cctype>
+ #include <functional>
++#include <iterator>
+ #include <map>
+ #include <set>
+ #include <unordered_map>
diff --git a/platforms/winpack_dldt/2021.4.2/patch.config.py b/platforms/winpack_dldt/2021.4.2/patch.config.py
index 7f8715aae2..bd31af236f 100644
--- a/platforms/winpack_dldt/2021.4.2/patch.config.py
+++ b/platforms/winpack_dldt/2021.4.2/patch.config.py
@@ -2,3 +2,4 @@ applyPatch('20210630-dldt-disable-unused-targets.patch')
 applyPatch('20210630-dldt-pdb.patch')
 applyPatch('20210630-dldt-disable-multidevice-autoplugin.patch')
 applyPatch('20210630-dldt-vs-version.patch')
+applyPatch('20220118-dldt-fix-msvs-compilation-21469.patch')