diff --git a/include/nana/paint/detail/image_processor.hpp b/include/nana/paint/detail/image_processor.hpp
index 4051eb90..3832456f 100644
--- a/include/nana/paint/detail/image_processor.hpp
+++ b/include/nana/paint/detail/image_processor.hpp
@@ -426,7 +426,7 @@ namespace detail
 				
 				unsigned char * fade_table = nullptr;
 				std::unique_ptr<unsigned char[]> autoptr;
-				nana::pixel_argb_t rgb_imd;
+				nana::pixel_argb_t rgb_imd = {};
 				if(fade_rate != 0.0)
 				{
 					autoptr = detail::alloc_fade_table(1 - fade_rate);
diff --git a/source/gui/detail/bedrock_posix.cpp b/source/gui/detail/bedrock_posix.cpp
index 4f74f5a9..5a3a4abe 100644
--- a/source/gui/detail/bedrock_posix.cpp
+++ b/source/gui/detail/bedrock_posix.cpp
@@ -237,7 +237,7 @@ namespace detail
 		if(wd_manager().available(wd) == false)
 			return false;
 
-		core_window_t * prev_wd;
+		core_window_t * prev_wd = nullptr;
 		if(thrd)
 		{
 			prev_wd = thrd->event_window;
diff --git a/source/gui/detail/bedrock_windows.cpp b/source/gui/detail/bedrock_windows.cpp
index 594c949f..11ef721a 100644
--- a/source/gui/detail/bedrock_windows.cpp
+++ b/source/gui/detail/bedrock_windows.cpp
@@ -760,7 +760,7 @@ namespace detail
 		if (bedrock::instance().wd_manager().available(wd) == false)
 			return;
 
-		basic_window* prev_event_wd;
+		basic_window* prev_event_wd = nullptr;
 		if (thrd)
 		{
 			prev_event_wd = thrd->event_window;
@@ -1630,7 +1630,7 @@ namespace detail
 		if (wd_manager().available(wd) == false)
 			return false;
 
-		basic_window* prev_event_wd;
+		basic_window* prev_event_wd = nullptr;
 		if (thrd)
 		{
 			prev_event_wd = thrd->event_window;
diff --git a/source/paint/pixel_buffer.cpp b/source/paint/pixel_buffer.cpp
index f29c4068..e62a927b 100644
--- a/source/paint/pixel_buffer.cpp
+++ b/source/paint/pixel_buffer.cpp
@@ -457,7 +457,7 @@ namespace nana{	namespace paint
 
 		HDC context = drawable->context;
 		HBITMAP pixmap = drawable->pixmap;
-		HBITMAP orig_bmp;
+		HBITMAP orig_bmp = nullptr;
 		if(need_dup)
 		{
 			context = ::CreateCompatibleDC(drawable->context);
@@ -795,7 +795,7 @@ namespace nana{	namespace paint
 		std::unique_ptr<unsigned char[]> autoptr;
 
 		auto rgb_color = clr.px_color().value;
-		nana::pixel_color_t rgb_imd;
+		nana::pixel_color_t rgb_imd = {};
 		if(fade)
 		{
 			autoptr = detail::alloc_fade_table(1 - fade_rate);
diff --git a/source/system/dataexch.cpp b/source/system/dataexch.cpp
index b647e1ec..dc52f293 100644
--- a/source/system/dataexch.cpp
+++ b/source/system/dataexch.cpp
@@ -195,7 +195,7 @@ namespace nana{ namespace system{
 					memcpy(addr, buf, size);
 					::GlobalUnlock(g);
 
-					unsigned data_format;
+					unsigned data_format = 0;
 					switch(fmt)
 					{
 					case format::text:		data_format = CF_UNICODETEXT;	break;
@@ -239,7 +239,7 @@ namespace nana{ namespace system{
 #if defined(NANA_WINDOWS)
 			if(::OpenClipboard(::GetFocus()))
 			{
-				unsigned data_format;
+				unsigned data_format = 0;
 				switch(fmt)
 				{
 				case format::text:		data_format = CF_UNICODETEXT;	break;
diff --git a/source/unicode_bidi.cpp b/source/unicode_bidi.cpp
index b98c6f29..3da7d2f0 100644
--- a/source/unicode_bidi.cpp
+++ b/source/unicode_bidi.cpp
@@ -515,7 +515,7 @@ namespace nana
 			cur.level = _m_paragraph_level(str, end);
 
 			//First character type
-			bidi_char begin_char_type;
+			bidi_char begin_char_type = {};
 			const char_type * begin_character = nullptr;
 
 			for(const char_type * c = str; c < end; ++c)
@@ -616,7 +616,7 @@ namespace nana
 			e.bidi_char_type = bidi_char_type;
 
 		}
-		
+
 		std::vector<unicode_bidi::entity>::iterator unicode_bidi::_m_search_first_character()
 		{
 			return levels_.begin();
@@ -811,7 +811,7 @@ namespace nana
 			//N1. A sequence of neutrals takes the direction of the surrounding strong text if the text on both sides has the same direction.
 			//European and Arabic numbers act as if they were R in terms of their influence on neutrals.
 			//Start-of-level-run (sor) and end-of-level-run (eor) are used at level run boundaries.
-			bidi_char left;
+			bidi_char left = {};
 			for(auto i = begin_character; i != end; ++i)
 			{
 				if(level_of_run != i->level)