diff --git a/src/boards/coolgirl.cpp b/src/boards/coolgirl.cpp
index 17c087d5..95dcf825 100644
--- a/src/boards/coolgirl.cpp
+++ b/src/boards/coolgirl.cpp
@@ -2286,7 +2286,7 @@ void COOLGIRL_Init(CartInfo *info) {
 	}
 
 	CFI = (uint8*)FCEU_gmalloc(sizeof(cfi_data) * 2);
-	for (int i = 0; i < sizeof(cfi_data); i++)
+	for (size_t i = 0; i < sizeof(cfi_data); i++)
 	{
 		CFI[i * 2] = CFI[i * 2 + 1] = cfi_data[i];
 	}
diff --git a/src/boards/mmc5.cpp b/src/boards/mmc5.cpp
index ac98d57d..35132731 100644
--- a/src/boards/mmc5.cpp
+++ b/src/boards/mmc5.cpp
@@ -307,8 +307,7 @@ cartdata MMC5CartList[] =
 
 #define MMC5_NOCARTS (sizeof(MMC5CartList) / sizeof(MMC5CartList[0]))
 int DetectMMC5WRAMSize(uint32 crc32) {
-	int x;
-	for (x = 0; x < MMC5_NOCARTS; x++) {
+	for (size_t x = 0; x < MMC5_NOCARTS; x++) {
 		if (crc32 == MMC5CartList[x].crc32) {
 			if(MMC5CartList[x].size > 1)
 				FCEU_printf(" >8KB external WRAM present.  Use UNIF if you hack the ROM image.\n");
diff --git a/src/drivers/Qt/GamePadConf.cpp b/src/drivers/Qt/GamePadConf.cpp
index 278e00af..cb9ad769 100644
--- a/src/drivers/Qt/GamePadConf.cpp
+++ b/src/drivers/Qt/GamePadConf.cpp
@@ -604,7 +604,7 @@ void GamePadConfDialog_t::loadMapList(void)
 	mapSel->addItem(tr("default"), 0);
 	n = 1;
 
-	for (size_t i = 0; i < fileList.size(); i++)
+	for (ssize_t i = 0; i < fileList.size(); i++)
 	{
 		size_t suffixIdx;
 		std::string fileName = fileList[i].toStdString();
diff --git a/src/drivers/Qt/fceuWrapper.cpp b/src/drivers/Qt/fceuWrapper.cpp
index 7fe7b440..ef80bd2a 100644
--- a/src/drivers/Qt/fceuWrapper.cpp
+++ b/src/drivers/Qt/fceuWrapper.cpp
@@ -888,9 +888,9 @@ int  fceuWrapperInit( int argc, char *argv[] )
 			extern std::vector<std::string> subtitleMessages;
 			float fps = (md.palFlag == 0 ? 60.0988 : 50.0069); // NTSC vs PAL
 			float subduration = 3; // seconds for the subtitles to be displayed
-			for (int i = 0; i < subtitleFrames.size(); i++)
+			for (size_t i = 0; i < subtitleFrames.size(); i++)
 			{
-				fprintf(srtfile, "%i\n", i+1); // starts with 1, not 0
+				fprintf(srtfile, "%zi\n", i+1); // starts with 1, not 0
 				double seconds, ms, endseconds, endms;
 				seconds = subtitleFrames[i]/fps;
 				if (i+1 < subtitleFrames.size()) // there's another subtitle coming after this one
diff --git a/src/drivers/Qt/sdl-sound.cpp b/src/drivers/Qt/sdl-sound.cpp
index 14347f72..99b3b495 100644
--- a/src/drivers/Qt/sdl-sound.cpp
+++ b/src/drivers/Qt/sdl-sound.cpp
@@ -223,7 +223,7 @@ InitSound()
 	i = 0;
 	while (supportedSampleRates[i] != 0)
 	{
-		if (soundrate == supportedSampleRates[i])
+		if ( static_cast<unsigned int>(soundrate) == supportedSampleRates[i])
 		{
 			sampleRateIsSupported = true;
 			break;
diff --git a/src/drivers/common/configSys.cpp b/src/drivers/common/configSys.cpp
index 4257df11..78048384 100644
--- a/src/drivers/common/configSys.cpp
+++ b/src/drivers/common/configSys.cpp
@@ -641,7 +641,7 @@ Config::_load()
 int
 Config::_loadFile(const char* fname)
 {
-	signed int pos, eqPos;
+	size_t pos=0, eqPos=0;
 	std::fstream config;
 	std::map<std::string, int>::iterator int_i;
 	std::map<std::string, double>::iterator dbl_i;