diff --git a/src/ObjSignature.h b/src/ObjSignature.h
index 80bcdb9c..2ad347be 100644
--- a/src/ObjSignature.h
+++ b/src/ObjSignature.h
@@ -93,7 +93,7 @@ public:
 
 		std::vector<unsigned char> bytes;
 		cv::imencode(".png", image_, bytes);
-		streamPtr << QByteArray((char*)bytes.data(), bytes.size());
+		streamPtr << QByteArray((char*)bytes.data(), (int)bytes.size());
 	}
 
 	void load(QDataStream & streamPtr)
diff --git a/src/Vocabulary.cpp b/src/Vocabulary.cpp
index d69cce0f..5fd7e1e9 100644
--- a/src/Vocabulary.cpp
+++ b/src/Vocabulary.cpp
@@ -286,8 +286,8 @@ void Vocabulary::search(const cv::Mat & descriptors, cv::Mat & results, cv::Mat
 			}
 
 			//convert back to matrix style
-			results = cv::Mat(matches.size(), k, CV_32SC1);
-			dists = cv::Mat(matches.size(), k, CV_32FC1);
+			results = cv::Mat((int)matches.size(), k, CV_32SC1);
+			dists = cv::Mat((int)matches.size(), k, CV_32FC1);
 			for(unsigned int i=0; i<matches.size(); ++i)
 			{
 				for(int j=0; j<k; ++j)
diff --git a/src/utilite/UConversion.cpp b/src/utilite/UConversion.cpp
index bec0536c..97296e50 100644
--- a/src/utilite/UConversion.cpp
+++ b/src/utilite/UConversion.cpp
@@ -155,7 +155,7 @@ std::string uBytes2Hex(const char * bytes, unsigned int bytesLen)
 
 std::vector<char> uHex2Bytes(const std::string & hex)
 {
-	return uHex2Bytes(&hex[0], hex.length());
+	return uHex2Bytes(&hex[0], (int)hex.length());
 }
 
 std::vector<char> uHex2Bytes(const char * hex, int hexLen)
@@ -270,7 +270,12 @@ std::string uFormatv (const char *fmt, va_list args)
 #endif
 
         // Try to vsnprintf into our buffer.
-    	int needed = vsnprintf (buf, size, fmt, argsTmp);
+#ifdef _MSC_VER
+		int needed = (int)vsnprintf_s(buf, size, _TRUNCATE, fmt, argsTmp);
+#else
+		int needed = (int)vsnprintf(buf, size, fmt, argsTmp);
+#endif
+
     	va_end(argsTmp);
         // NB. C99 (which modern Linux and OS X follow) says vsnprintf
         // failure returns the length it would have needed.  But older
diff --git a/src/utilite/UDirectory.cpp b/src/utilite/UDirectory.cpp
index 99f6b684..7ada8ade 100644
--- a/src/utilite/UDirectory.cpp
+++ b/src/utilite/UDirectory.cpp
@@ -262,7 +262,7 @@ bool UDirectory::exists(const std::string & dirPath)
 std::string UDirectory::getDir(const std::string & filePath)
 {
 	std::string dir = filePath;
-	int i=dir.size()-1;
+	int i=(int)dir.size()-1;
 	for(; i>=0; --i)
 	{
 		if(dir[i] == '/' || dir[i] == '\\')
diff --git a/src/utilite/UFile.cpp b/src/utilite/UFile.cpp
index 3f9a395f..0de771ba 100644
--- a/src/utilite/UFile.cpp
+++ b/src/utilite/UFile.cpp
@@ -65,14 +65,14 @@ int UFile::erase(const std::string &filePath)
 int UFile::rename(const std::string &oldFilePath,
                      const std::string &newFilePath)
 {
-    return rename(oldFilePath.c_str(), newFilePath.c_str());
+    return ::rename(oldFilePath.c_str(), newFilePath.c_str());
 }
 
 std::string UFile::getName(const std::string & filePath)
 {
 	std::string fullPath = filePath;
 	std::string name;
-	for(int i=fullPath.size()-1; i>=0; --i)
+	for(int i=(int)fullPath.size()-1; i>=0; --i)
 	{
 		if(fullPath[i] == '/' || fullPath[i] == '\\')
 		{
diff --git a/tools/similarity/main.cpp b/tools/similarity/main.cpp
index 22e83bad..61da202e 100644
--- a/tools/similarity/main.cpp
+++ b/tools/similarity/main.cpp
@@ -127,7 +127,7 @@ int main(int argc, char * argv[])
 		////////////////////////////
 
 		// Find correspondences by NNDR (Nearest Neighbor Distance Ratio)
-		float nndrRatio = 0.6;
+		float nndrRatio = 0.6f;
 		std::vector<cv::Point2f> mpts_1, mpts_2; // Used for homography
 		std::vector<int> indexes_1, indexes_2; // Used for homography
 		std::vector<uchar> outlier_mask;  // Used for homography
@@ -176,7 +176,7 @@ int main(int argc, char * argv[])
 		}
 		else
 		{
-			value = mpts_1.size();
+			value = (int)mpts_1.size();
 		}
 	}
 	else