diff --git a/modules/dnn/3rdparty/protobuf/CMakeLists.txt b/modules/dnn/3rdparty/protobuf/CMakeLists.txt
index 1ec897298..d247c0129 100644
--- a/modules/dnn/3rdparty/protobuf/CMakeLists.txt
+++ b/modules/dnn/3rdparty/protobuf/CMakeLists.txt
@@ -89,16 +89,16 @@ if(WIN32 AND BUILD_SHARED_LIBS AND MSVC)
     add_definitions(-DLIBPROTOBUF_EXPORTS)
 endif()
 
-add_definitions( -D_GNU_SOURCE=1 )
-add_definitions( -DHAVE_CONFIG_H )
+#add_definitions( -DGOOGLE_PROTOBUF_NO_THREAD_SAFETY ) #we don't need thread safety
+add_definitions( -D_GNU_SOURCE=1 ) #it's maybe useful
+add_definitions( -DHAVE_CONFIG_H ) #we will use config.h
 configure_file("cmake/config.h.in" "config.h")
 
 if(MSVC)
   add_definitions( -D_CRT_SECURE_NO_WARNINGS=1 )
-  ocv_warnings_disable(CMAKE_CXX_FLAGS /wd4244 /wd4267 /wd4018 /wd4355 /wd4800 /wd4251 /wd4996 /wd4146 /wd4305 /wd4127 /wd4100 /wd4512 /wd4125 /w4398 /w4510 /w4610 /w4244 /w4702 /w4389)
+  ocv_warnings_disable(CMAKE_CXX_FLAGS /wd4244 /wd4267 /wd4018 /wd4355 /wd4800 /wd4251 /wd4996 /wd4146 /wd4305 /wd4127 /wd4100 /wd4512 /wd4125 /wd4389 /wd4510 /wd4610 /wd4702)
 else()
   ocv_warnings_disable(CMAKE_CXX_FLAGS -Wno-deprecated -Wmissing-prototypes -Wmissing-declarations -Wshadow -Wunused-parameter -Wunused-local-typedefs -Wsign-compare -Wsign-promo -Wundef)
-  ocv_warnings_disable(CMAKE_C_FLAGS -Wunused-parameter) # clang
 endif()
 
 # Easier to support different versions of protobufs
@@ -116,6 +116,12 @@ endfunction()
 
 set(PROTOBUF_ROOT ${CMAKE_CURRENT_SOURCE_DIR})
 
+if(MSVC)
+  set(ATOMICOPS_INTERNALS ${PROTOBUF_ROOT}/src/google/protobuf/stubs/atomicops_internals_x86_msvc.cc)
+else()
+  set(ATOMICOPS_INTERNALS ${PROTOBUF_ROOT}/src/google/protobuf/stubs/atomicops_internals_x86_gcc.cc)
+endif()
+
 append_if_exist(PROTOBUF_SRCS
   ${PROTOBUF_ROOT}/src/google/protobuf/compiler/importer.cc
   ${PROTOBUF_ROOT}/src/google/protobuf/compiler/parser.cc
@@ -139,8 +145,7 @@ append_if_exist(PROTOBUF_SRCS
   ${PROTOBUF_ROOT}/src/google/protobuf/reflection_ops.cc
   ${PROTOBUF_ROOT}/src/google/protobuf/repeated_field.cc
   ${PROTOBUF_ROOT}/src/google/protobuf/service.cc
-  ${PROTOBUF_ROOT}/src/google/protobuf/stubs/atomicops_internals_x86_gcc.cc
-  ${PROTOBUF_ROOT}/src/google/protobuf/stubs/atomicops_internals_x86_msvc.cc
+  ${ATOMICOPS_INTERNALS}
   ${PROTOBUF_ROOT}/src/google/protobuf/stubs/common.cc
   ${PROTOBUF_ROOT}/src/google/protobuf/stubs/once.cc
   ${PROTOBUF_ROOT}/src/google/protobuf/stubs/stringprintf.cc
@@ -151,7 +156,7 @@ append_if_exist(PROTOBUF_SRCS
   ${PROTOBUF_ROOT}/src/google/protobuf/unknown_field_set.cc
   ${PROTOBUF_ROOT}/src/google/protobuf/wire_format.cc
   ${PROTOBUF_ROOT}/src/google/protobuf/wire_format_lite.cc
-#  ${PROTOBUF_ROOT}/src/google/protobuf/stubs/hash.cc
+  #${PROTOBUF_ROOT}/src/google/protobuf/stubs/hash.cc
 )
 
 if(UNIX AND (CMAKE_COMPILER_IS_GNUCXX OR CV_ICC))
diff --git a/modules/dnn/CMakeLists.txt b/modules/dnn/CMakeLists.txt
index 4f1acb799..06aa91714 100644
--- a/modules/dnn/CMakeLists.txt
+++ b/modules/dnn/CMakeLists.txt
@@ -10,6 +10,7 @@ include(cmake/find_protobuf.cmake)
 
 ocv_add_module(dnn opencv_imgproc opencv_core opencv_highgui WRAP python matlab)
 ocv_warnings_disable(CMAKE_CXX_FLAGS -Wno-shadow -Wno-parentheses -Wmaybe-uninitialized -Wsign-promo -Wmissing-declarations -Wmissing-prototypes)
+ocv_warnings_disable(CMAKE_CXX_FLAGS /wd4701)
 ocv_glob_module_sources(${PROTOBUF_SRCS} ${PROTOBUF_HDRS})
 ocv_source_group("Src\\protobuf" FILES ${PROTOBUF_SRCS} ${PROTOBUF_HDRS})
 ocv_module_include_directories(include ${PROTOBUF_INCLUDE_DIR})
@@ -31,6 +32,7 @@ endif()
 OCV_OPTION(${the_module}_BUILD_TORCH_IMPORTER "Build Torch model importer" OFF)
 if(${the_module}_BUILD_TORCH_IMPORTER)
     add_definitions(-DENABLE_TORCH_IMPORTER=1)
+    ocv_warnings_disable(CMAKE_CXX_FLAGS /wd4702 /wd4127 /wd4267)
 endif()
 
 OCV_OPTION(${the_module}_BUILD_TORCH_TESTS "Build Torch tests (installed Torch7 with nn module is required)" ON IF BUILD_TESTS AND ${the_module}_BUILD_TORCH_IMPORTER)
diff --git a/modules/dnn/cmake/.gitignore b/modules/dnn/cmake/.gitignore
deleted file mode 100644
index fe06a514f..000000000
--- a/modules/dnn/cmake/.gitignore
+++ /dev/null
@@ -1,2 +0,0 @@
-build
-build-*
diff --git a/modules/dnn/cmake/find_protobuf.cmake b/modules/dnn/cmake/find_protobuf.cmake
index 28c5b0ea4..8adb5ad45 100644
--- a/modules/dnn/cmake/find_protobuf.cmake
+++ b/modules/dnn/cmake/find_protobuf.cmake
@@ -31,4 +31,7 @@ else()
     VERBATIM
   )
   set_source_files_properties(${PROTOBUF_SRCS} ${PROTOBUF_HDRS} PROPERTIES GENERATED TRUE)
+
+  ocv_warnings_disable(CMAKE_CXX_FLAGS -Wunused-parameter)
+  ocv_warnings_disable(CMAKE_CXX_FLAGS /wd4125 /wd4267 /wd4127 /wd4244 /wd4512 /wd4702)
 endif()
\ No newline at end of file
diff --git a/modules/dnn/src/torch/torch_importer.cpp b/modules/dnn/src/torch/torch_importer.cpp
index e1b70dab6..522c8d31a 100644
--- a/modules/dnn/src/torch/torch_importer.cpp
+++ b/modules/dnn/src/torch/torch_importer.cpp
@@ -99,7 +99,7 @@ struct TorchImporter : public ::cv::dnn::Importer
 
     inline bool readBool()
     {
-        return readInt();
+        return readInt() != 0;
     }
 
     inline double readDouble()
@@ -439,7 +439,7 @@ struct TorchImporter : public ::cv::dnn::Importer
                 CV_Assert(tensorParams.count("weight"));
                 layerParams.learnedBlobs.push_back(tensorParams["weight"]);
 
-                bool bias = tensorParams.count("bias");
+                bool bias = tensorParams.count("bias") != 0;
                 layerParams.set("bias_term", bias);
                 if (bias)
                     layerParams.learnedBlobs.push_back(tensorParams["bias"]);
@@ -471,7 +471,7 @@ struct TorchImporter : public ::cv::dnn::Importer
                 Blob weightBlob = tensorParams["weight"];
                 layerParams.learnedBlobs.push_back(weightBlob);
 
-                bool bias = tensorParams.count("bias");
+                bool bias = tensorParams.count("bias") != 0;
                 if (bias)
                     layerParams.learnedBlobs.push_back(tensorParams["bias"]);
                 layerParams.set("bias_term", bias);