diff --git a/doc/Doxyfile b/doc/Doxyfile
index 8dfc0dcd10..757a0103f6 100644
--- a/doc/Doxyfile
+++ b/doc/Doxyfile
@@ -281,7 +281,7 @@ SKIP_FUNCTION_MACROS   = YES
 # Configuration options related to external references
 #---------------------------------------------------------------------------
 TAGFILES               =
-GENERATE_TAGFILE       =
+GENERATE_TAGFILE       = html/nlohmann_json.tag
 ALLEXTERNALS           = NO
 EXTERNAL_GROUPS        = YES
 EXTERNAL_PAGES         = YES
diff --git a/src/json.hpp b/src/json.hpp
index 1fa90456ec..47d51737d9 100644
--- a/src/json.hpp
+++ b/src/json.hpp
@@ -206,9 +206,9 @@ class exception : public std::exception
   protected:
     exception(int id_, const char* what_arg) : id(id_), m(what_arg) {}
 
-    static std::string name(const std::string& ename, int id)
+    static std::string name(const std::string& ename, int id_)
     {
-        return "[json.exception." + ename + "." + std::to_string(id) + "] ";
+        return "[json.exception." + ename + "." + std::to_string(id_) + "] ";
     }
 
   private:
@@ -264,18 +264,18 @@ class parse_error : public exception
   public:
     /*!
     @brief create a parse error exception
-    @param[in] id        the id of the exception
+    @param[in] id_       the id of the exception
     @param[in] byte_     the byte index where the error occurred (or 0 if the
                          position cannot be determined)
     @param[in] what_arg  the explanatory string
     @return parse_error object
     */
-    static parse_error create(int id, std::size_t byte_, const std::string& what_arg)
+    static parse_error create(int id_, std::size_t byte_, const std::string& what_arg)
     {
-        std::string w = exception::name("parse_error", id) + "parse error" +
+        std::string w = exception::name("parse_error", id_) + "parse error" +
                         (byte_ != 0 ? (" at " + std::to_string(byte_)) : "") +
                         ": " + what_arg;
-        return parse_error(id, byte_, w.c_str());
+        return parse_error(id_, byte_, w.c_str());
     }
 
     /*!
@@ -334,10 +334,10 @@ caught.,invalid_iterator}
 class invalid_iterator : public exception
 {
   public:
-    static invalid_iterator create(int id, const std::string& what_arg)
+    static invalid_iterator create(int id_, const std::string& what_arg)
     {
-        std::string w = exception::name("invalid_iterator", id) + what_arg;
-        return invalid_iterator(id, w.c_str());
+        std::string w = exception::name("invalid_iterator", id_) + what_arg;
+        return invalid_iterator(id_, w.c_str());
     }
 
   private:
@@ -385,10 +385,10 @@ caught.,type_error}
 class type_error : public exception
 {
   public:
-    static type_error create(int id, const std::string& what_arg)
+    static type_error create(int id_, const std::string& what_arg)
     {
-        std::string w = exception::name("type_error", id) + what_arg;
-        return type_error(id, w.c_str());
+        std::string w = exception::name("type_error", id_) + what_arg;
+        return type_error(id_, w.c_str());
     }
 
   private:
@@ -428,10 +428,10 @@ caught.,out_of_range}
 class out_of_range : public exception
 {
   public:
-    static out_of_range create(int id, const std::string& what_arg)
+    static out_of_range create(int id_, const std::string& what_arg)
     {
-        std::string w = exception::name("out_of_range", id) + what_arg;
-        return out_of_range(id, w.c_str());
+        std::string w = exception::name("out_of_range", id_) + what_arg;
+        return out_of_range(id_, w.c_str());
     }
 
   private:
@@ -466,10 +466,10 @@ caught.,other_error}
 class other_error : public exception
 {
   public:
-    static other_error create(int id, const std::string& what_arg)
+    static other_error create(int id_, const std::string& what_arg)
     {
-        std::string w = exception::name("other_error", id) + what_arg;
-        return other_error(id, w.c_str());
+        std::string w = exception::name("other_error", id_) + what_arg;
+        return other_error(id_, w.c_str());
     }
 
   private:
@@ -3008,11 +3008,19 @@ class parser
         {
             case token_type::begin_object:
             {
-                if (keep and (not callback or ((keep = callback(depth++, parse_event_t::object_start, result)))))
+                if (keep)
                 {
-                    // explicitly set result to object to cope with {}
-                    result.m_type = value_t::object;
-                    result.m_value = value_t::object;
+                    if (callback)
+                    {
+                        keep = callback(depth++, parse_event_t::object_start, result);
+                    }
+
+                    if (not callback or keep)
+                    {
+                        // explicitly set result to object to cope with {}
+                        result.m_type = value_t::object;
+                        result.m_value = value_t::object;
+                    }
                 }
 
                 // read next token
@@ -3104,11 +3112,19 @@ class parser
 
             case token_type::begin_array:
             {
-                if (keep and (not callback or ((keep = callback(depth++, parse_event_t::array_start, result)))))
+                if (keep)
                 {
-                    // explicitly set result to object to cope with []
-                    result.m_type = value_t::array;
-                    result.m_value = value_t::array;
+                    if (callback)
+                    {
+                        keep = callback(depth++, parse_event_t::array_start, result);
+                    }
+
+                    if (not callback or keep)
+                    {
+                        // explicitly set result to array to cope with []
+                        result.m_type = value_t::array;
+                        result.m_value = value_t::array;
+                    }
                 }
 
                 // read next token
@@ -5250,7 +5266,7 @@ class binary_reader
         {
             get();
             check_eof();
-            return current;
+            return static_cast<char>(current);
         });
         return result;
     }
diff --git a/test/CMakeLists.txt b/test/CMakeLists.txt
index 4ccbaf06d1..c72867839f 100644
--- a/test/CMakeLists.txt
+++ b/test/CMakeLists.txt
@@ -66,6 +66,22 @@ set_target_properties(catch_main PROPERTIES
 )
 target_include_directories(catch_main PRIVATE "thirdparty/catch")
 
+# https://stackoverflow.com/questions/2368811/how-to-set-warning-level-in-cmake
+if(MSVC)
+    # Force to always compile with W4
+    if(CMAKE_CXX_FLAGS MATCHES "/W[0-4]")
+        string(REGEX REPLACE "/W[0-4]" "/W4" CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS}")
+    else()
+        set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} /W4")
+    endif()
+
+    # Disable warning C4389: '==': signed/unsigned mismatch
+	# Disable warning C4309: 'static_cast': truncation of constant value
+	# Disable warning C4566: character represented by universal-character-name '\uFF01' cannot be represented in the current code page (1252)
+	# Disable warning C4996: 'nlohmann::basic_json<std::map,std::vector,std::string,bool,int64_t,uint64_t,double,std::allocator,nlohmann::adl_serializer>::operator <<': was declared deprecated
+    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} /wd4389 /wd4309 /wd4566 /wd4996")
+endif()
+
 #############################################################################
 # one executable for each unit test file
 #############################################################################
diff --git a/test/src/unit-constructor1.cpp b/test/src/unit-constructor1.cpp
index ec096dcd45..ed2c80078d 100644
--- a/test/src/unit-constructor1.cpp
+++ b/test/src/unit-constructor1.cpp
@@ -242,7 +242,7 @@ TEST_CASE("constructors")
 
         SECTION("std::pair")
         {
-            std::pair<float, std::string> p{1.0, "string"};
+            std::pair<float, std::string> p{1.0f, "string"};
             json j(p);
 
             CHECK(j.type() == json::value_t::array);
diff --git a/test/src/unit-readme.cpp b/test/src/unit-readme.cpp
index e921c4b687..5a442c601e 100644
--- a/test/src/unit-readme.cpp
+++ b/test/src/unit-readme.cpp
@@ -38,6 +38,11 @@ using nlohmann::json;
 #include <unordered_set>
 #include <iostream>
 
+#if defined(_MSC_VER)
+#pragma warning (push)
+#pragma warning (disable : 4189) // local variable is initialized but not referenced
+#endif
+
 TEST_CASE("README", "[hide]")
 {
     {
@@ -298,3 +303,7 @@ TEST_CASE("README", "[hide]")
         std::cout.rdbuf(old_cout_buffer);
     }
 }
+
+#if defined(_MSC_VER)
+#pragma warning (pop)
+#endif
diff --git a/test/src/unit-udt.cpp b/test/src/unit-udt.cpp
index 6aa469fe4e..409cac8397 100644
--- a/test/src/unit-udt.cpp
+++ b/test/src/unit-udt.cpp
@@ -201,7 +201,7 @@ void from_json(const BasicJsonType& j, country& c)
     {
         {u8"中华人民共和国", country::china},
         {"France", country::france},
-        {"Российская Федерация", country::russia}
+        {u8"Российская Федерация", country::russia}
     };
 
     const auto it = m.find(str);