diff --git a/CMakeLists.txt b/CMakeLists.txt
index 8351a520..58ab0049 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -171,14 +171,9 @@ function(RELATIVE_PROTOBUF_GENERATE_CPP NAME SRCS HDRS ROOT_DIR DEPEND)
     file(RELATIVE_PATH REL_DIR ${ROOT_DIR} ${FILE_DIR})
     set(OUTPUT_PROTO_DIR "${CMAKE_CURRENT_BINARY_DIR}/${REL_DIR}")
 
-    set(OUTPUT_PB_HEADER "${OUTPUT_PROTO_DIR}/${GENERATED_FILE_WE}.pb.h")
+    set(OUTPUT_PB_HEADER "${PROTOBUF_INCLUDE_DIRS}/${GENERATED_FILE_WE}.pb.h")
     set(OUTPUT_PB_SRC "${OUTPUT_PROTO_DIR}/${GENERATED_FILE_WE}.pb.cc")
     set(GENERATED_PROTO "${OUTPUT_PROTO_DIR}/${GENERATED_FILE_WE}.proto")
-    if(NOT (ONNX_NAMESPACE STREQUAL "onnx"))
-      # We need this dummy header generated by gen_proto.py when ONNX_NAMESPACE
-      # is not onnx
-      list(APPEND ${HDRS} "${OUTPUT_PROTO_DIR}/${GENERATED_FILE_WE}.pb.h")
-    endif()
     list(APPEND ${SRCS} "${OUTPUT_PB_SRC}")
     list(APPEND ${HDRS} "${OUTPUT_PB_HEADER}")
 
@@ -217,7 +212,7 @@ function(RELATIVE_PROTOBUF_GENERATE_CPP NAME SRCS HDRS ROOT_DIR DEPEND)
                        DEPENDS ${INFILE}
                        COMMENT "Running gen_proto.py on ${INFILE}"
                        VERBATIM)
-    message("Generated: ${GENERATED_PROTO}")
+    message("Generated: ${GENERATED_PROTO}\n")
     set(PROTOC_ARGS
         ${GENERATED_PROTO}
         -I
@@ -368,6 +363,14 @@ target_include_directories(onnx PUBLIC
 target_link_libraries(onnx PUBLIC onnx_proto)
 add_onnx_global_defines(onnx)
 
+add_library(onnx_c "${ONNX_ROOT}/onnx/onnx-c.h" "${ONNX_ROOT}/onnx/onnx-c.cc")
+target_include_directories(onnx_c PUBLIC
+  $<BUILD_INTERFACE:${ONNX_ROOT}>
+  $<BUILD_INTERFACE:${CMAKE_CURRENT_BINARY_DIR}>
+  $<INSTALL_INTERFACE:include>)
+target_link_libraries(onnx_c PUBLIC onnx onnx_proto)
+add_onnx_global_defines(onnx_c)
+
 if(BUILD_ONNX_PYTHON)
   if("${PY_EXT_SUFFIX}" STREQUAL "")
     if(MSVC)
@@ -434,7 +437,6 @@ if(BUILD_ONNX_PYTHON)
     target_link_libraries(onnx_cpp2py_export PRIVATE ${PYTHON_LIBRARIES})
     target_compile_options(onnx_cpp2py_export
                            PRIVATE /MP
-                                   /WX
                                    /wd4800 # disable warning type' : forcing
                                            # value to bool 'true' or 'false'
                                            # (performance warning)
@@ -481,7 +483,6 @@ endif()
 if(MSVC)
   target_compile_options(onnx_proto
                          PRIVATE /MP
-                                 /WX
                                  /wd4800 # disable warning type' : forcing value
                                          # to bool 'true' or 'false'
                                          # (performance warning)
@@ -494,7 +495,6 @@ if(MSVC)
                                  ${EXTRA_FLAGS})
   target_compile_options(onnx
                          PRIVATE /MP
-                                 /WX
                                  /wd4800 # disable warning type' : forcing value
                                          # to bool 'true' or 'false'
                                          # (performance warning)
@@ -619,6 +619,7 @@ install(EXPORT ONNXTargets DESTINATION share/cmake/ONNX)
 install(TARGETS
   onnx onnx_proto
   onnxifi onnxifi_dummy onnxifi_loader
+  onnx_c
   EXPORT ONNXTargets DESTINATION lib)
 
 if(NOT ANDROID AND NOT IOS)
diff --git a/onnx/onnx-c.cc b/onnx/onnx-c.cc
new file mode 100644
index 00000000..941e3311
--- /dev/null
+++ b/onnx/onnx-c.cc
@@ -0,0 +1,18 @@
+#include "onnx/onnx-c.h"
+#include "onnx/proto_utils.h"
+#include "onnx/shape_inference/implementation.h"
+
+extern "C" {
+
+using namespace onnx;
+
+size_t onnx_proto_shape_inference(const char* buffer, size_t size, char* output) {
+  ModelProto proto{};
+  bool status = ParseProtoFromBytes(&proto, buffer, size);
+  shape_inference::InferShapes(proto);
+  int written = proto.ByteSizeLong();
+  proto.SerializeToArray(output, written);
+  return static_cast<size_t>(written);
+}
+
+} // extern "C"
diff --git a/onnx/onnx-c.h b/onnx/onnx-c.h
new file mode 100644
index 00000000..6e42ef55
--- /dev/null
+++ b/onnx/onnx-c.h
@@ -0,0 +1,26 @@
+
+#ifndef THIRD_PARTY_ONNX_C_H_
+#define THIRD_PARTY_ONNX_C_H_
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#include <stddef.h>
+
+/**
+ * @brief  Inferes shape from protocol buffers model.
+ *
+ * @param  buffer: Pointer to protocol buffers message.
+ * @param  size: Size of the protocol buffers message.
+ * @param  output: Pointer to output buffer.
+ * @retval Bytes written to output buffer.
+ */
+size_t
+onnx_proto_shape_inference(const char* buffer, size_t size, char* output);
+
+#ifdef __cplusplus
+} // extern "C"
+#endif
+
+#endif /* THIRD_PARTY_ONNX_C_H_ */
\ No newline at end of file