diff --git a/source/core/automap.cpp b/source/core/automap.cpp
index 1b7ba5519..f9ef9e153 100644
--- a/source/core/automap.cpp
+++ b/source/core/automap.cpp
@@ -185,7 +185,7 @@ static void CalcMapBounds()
 void AutomapControl()
 {
 	static int nonsharedtimer;
-	int ms = screen->FrameTime;
+	int ms = (int)screen->FrameTime;
 	int interval;
 	int panvert = 0, panhorz = 0;
 
@@ -197,7 +197,7 @@ void AutomapControl()
 	{
 		interval = 0;
 	}
-	nonsharedtimer = screen->FrameTime;
+	nonsharedtimer = ms;
 
 	if (System_WantGuiCapture())
 		return;
diff --git a/source/core/cheats.cpp b/source/core/cheats.cpp
index 9b670931c..013a145fc 100644
--- a/source/core/cheats.cpp
+++ b/source/core/cheats.cpp
@@ -196,7 +196,7 @@ CCMD(give)
 	if (!CheckCheatmode(true, true))
 	{
 		Net_WriteByte(DEM_GIVE);
-		Net_WriteByte(found);
+		Net_WriteByte((uint8_t)found);
 	}
 }
 
diff --git a/source/core/gamecontrol.cpp b/source/core/gamecontrol.cpp
index a6fc77df4..68c4a3b76 100644
--- a/source/core/gamecontrol.cpp
+++ b/source/core/gamecontrol.cpp
@@ -1523,7 +1523,7 @@ DEFINE_ACTION_FUNCTION_NATIVE(_Raze, MusicEnabled, MusicEnabled)
 
 DEFINE_ACTION_FUNCTION_NATIVE(_Raze, GetTimeFrac, I_GetTimeFrac)
 {
-	ACTION_RETURN_INT(I_GetTimeFrac());
+	ACTION_RETURN_FLOAT(I_GetTimeFrac());
 }
 
 DEFINE_ACTION_FUNCTION(_Raze, PlayerName)
diff --git a/source/core/gamecvars.cpp b/source/core/gamecvars.cpp
index f4b0c3de0..6eaec0d76 100644
--- a/source/core/gamecvars.cpp
+++ b/source/core/gamecvars.cpp
@@ -146,7 +146,7 @@ CCMD(sizeup)
 	}
 	else
 	{
-		hud_scalefactor = hud_scalefactor + 0.04;
+		hud_scalefactor = hud_scalefactor + 0.04f;
 	}
 }
 
@@ -162,7 +162,7 @@ CCMD(sizedown)
 	}
 	else
 	{
-		hud_scalefactor = hud_scalefactor - 0.04;
+		hud_scalefactor = hud_scalefactor - 0.04f;
 	}
 }
 
diff --git a/source/core/gamefuncs.cpp b/source/core/gamefuncs.cpp
index f34cd1249..7015acacb 100644
--- a/source/core/gamefuncs.cpp
+++ b/source/core/gamefuncs.cpp
@@ -131,7 +131,7 @@ bool calcChaseCamPos(int* px, int* py, int* pz, spritetype* pspr, short *psectnu
 	*pz += MulScale(nz, cameradist, 16);
 
 	// Caculate clock using GameTicRate so it increases the same rate on all speed computers.
-	int myclock = PlayClock + MulScale(120 / GameTicRate, smoothratio, 16);
+	int myclock = PlayClock + MulScale(120 / GameTicRate, int(smoothratio), 16);
 	if (cameraclock == INT_MIN)
 	{
 		// Third person view was just started.
@@ -154,7 +154,7 @@ bool calcChaseCamPos(int* px, int* py, int* pz, spritetype* pspr, short *psectnu
 //
 //==========================================================================
 
-void PlanesAtPoint(const sectortype* sec, float dax, float day, float* pceilz, float* pflorz)
+void PlanesAtPoint(const sectortype* sec, int dax, int day, float* pceilz, float* pflorz)
 {
 	float ceilz = float(sec->ceilingz);
 	float florz = float(sec->floorz);
@@ -164,13 +164,13 @@ void PlanesAtPoint(const sectortype* sec, float dax, float day, float* pceilz, f
 		auto wal = &wall[sec->wallptr];
 		auto wal2 = &wall[wal->point2];
 
-		float dx = wal2->x - wal->x;
-		float dy = wal2->y - wal->y;
+		float dx = float(wal2->x - wal->x);
+		float dy = float(wal2->y - wal->y);
 
 		int i = (int)sqrt(dx * dx + dy * dy) << 5; // length of sector's first wall.
 		if (i != 0)
 		{
-			float const j = (dx * (day - wal->y) - dy * (dax - wal->x)) * (1.f / 8.f);
+			float const j = (dx * (float(day - wal->y)) - dy * (float(dax - wal->x))) * (1.f / 8.f);
 			if (sec->ceilingstat & CSTAT_SECTOR_SLOPE) ceilz += (sec->ceilingheinum * j) / i;
 			if (sec->floorstat & CSTAT_SECTOR_SLOPE) florz += (sec->floorheinum * j) / i;
 		}
diff --git a/source/core/gamefuncs.h b/source/core/gamefuncs.h
index 20a5d7ad7..26265ae26 100644
--- a/source/core/gamefuncs.h
+++ b/source/core/gamefuncs.h
@@ -9,7 +9,7 @@ extern int cameradist, cameraclock;
 void loaddefinitionsfile(const char* fn, bool cumulative = false);
 
 bool calcChaseCamPos(int* px, int* py, int* pz, spritetype* pspr, short *psectnum, binangle ang, fixedhoriz horiz, double const smoothratio);
-void PlanesAtPoint(const sectortype* sec, float dax, float day, float* ceilz, float* florz);
+void PlanesAtPoint(const sectortype* sec, int dax, int day, float* ceilz, float* florz);
 void setWallSectors();
 void GetWallSpritePosition(const spritetype* spr, vec2_t pos, vec2_t* out, bool render = false);
 void GetFlatSpritePosition(const spritetype* spr, vec2_t pos, vec2_t* out, bool render = false);
diff --git a/source/core/gameinput.cpp b/source/core/gameinput.cpp
index 8560220a2..236e50082 100644
--- a/source/core/gameinput.cpp
+++ b/source/core/gameinput.cpp
@@ -61,7 +61,7 @@ binangle getincanglebam(binangle a, binangle na)
 		if(cura > INT32_MAX) cura -= UINT32_MAX;
 	}
 
-	return bamang(newa-cura);
+	return bamang(uint32_t(newa-cura));
 }
 
 //---------------------------------------------------------------------------
@@ -133,7 +133,7 @@ void processMovement(InputPacket* currInput, InputPacket* inputBuffer, ControlIn
 	if (buttonMap.ButtonDown(gamefunc_Strafe) && allowstrafe)
 		currInput->svel -= xs_CRoundToInt((hidInput->mousemovex * mousevelscale) + (scaleAdjust * hidInput->dyaw * keymove * cntrlvelscale));
 	else
-		currInput->avel += hidInput->mouseturnx + (scaleAdjust * hidInput->dyaw * hidspeed * turnscale);
+		currInput->avel += float(hidInput->mouseturnx + (scaleAdjust * hidInput->dyaw * hidspeed * turnscale));
 
 	if (!(inputBuffer->actions & SB_AIMMODE))
 		currInput->horz -= hidInput->mouseturny;
@@ -147,7 +147,7 @@ void processMovement(InputPacket* currInput, InputPacket* inputBuffer, ControlIn
 		currInput->avel = -currInput->avel;
 
 	// process remaining controller input.
-	currInput->horz -= scaleAdjust * hidInput->dpitch * hidspeed;
+	currInput->horz -= float(scaleAdjust * hidInput->dpitch * hidspeed);
 	currInput->svel += xs_CRoundToInt(scaleAdjust * hidInput->dx * keymove * cntrlvelscale);
 	currInput->fvel += xs_CRoundToInt(scaleAdjust * hidInput->dz * keymove * cntrlvelscale);
 
@@ -177,12 +177,12 @@ void processMovement(InputPacket* currInput, InputPacket* inputBuffer, ControlIn
 		if (buttonMap.ButtonDown(gamefunc_Turn_Left) || (buttonMap.ButtonDown(gamefunc_Strafe_Left) && !allowstrafe))
 		{
 			updateTurnHeldAmt(scaleAdjust);
-			currInput->avel -= scaleAdjust * (isTurboTurnTime() ? turnamount : preambleturn);
+			currInput->avel -= float(scaleAdjust * (isTurboTurnTime() ? turnamount : preambleturn));
 		}
 		else if (buttonMap.ButtonDown(gamefunc_Turn_Right) || (buttonMap.ButtonDown(gamefunc_Strafe_Right) && !allowstrafe))
 		{
 			updateTurnHeldAmt(scaleAdjust);
-			currInput->avel += scaleAdjust * (isTurboTurnTime() ? turnamount : preambleturn);
+			currInput->avel += float(scaleAdjust * (isTurboTurnTime() ? turnamount : preambleturn));
 		}
 		else
 		{
diff --git a/source/core/initfs.cpp b/source/core/initfs.cpp
index 4a59514c0..f5796dc6a 100644
--- a/source/core/initfs.cpp
+++ b/source/core/initfs.cpp
@@ -263,7 +263,7 @@ static void DeleteStuff(FileSystem &fileSystem, const TArray<FString>& deletelum
 			str.Truncate(ndx);
 		}
 
-		for (uint32_t i = 0; i < fileSystem.GetNumEntries(); i++)
+		for (int i = 0; i < fileSystem.GetNumEntries(); i++)
 		{
 			int cf = fileSystem.GetFileContainer(i);
 			auto fname = fileSystem.GetFileFullName(i, false);
@@ -343,8 +343,8 @@ void InitFileSystem(TArray<GrpEntry>& groups)
 
 	D_AddConfigFiles(Files, "Global.Autoload", "*.grp", GameConfig);
 
-	long len;
-	int lastpos = 0;
+	size_t len;
+	size_t lastpos = 0;
 
 	while (lastpos < LumpFilter.Len() && (len = strcspn(LumpFilter.GetChars() + lastpos, ".")) > 0)
 	{
diff --git a/source/core/mapinfo.cpp b/source/core/mapinfo.cpp
index 3231c990a..d327d5587 100644
--- a/source/core/mapinfo.cpp
+++ b/source/core/mapinfo.cpp
@@ -168,7 +168,7 @@ MapRecord* FindNextSecretMap(MapRecord* thismap)
 bool SetMusicForMap(const char* mapname, const char* music, bool namehack)
 {
 	static const char* specials[] = { "intro", "briefing", "loading" };
-	for (int i = 0; i < 3; i++)
+	for (unsigned i = 0; i < 3; i++)
 	{
 		if (!stricmp(mapname, specials[i]))
 		{
diff --git a/source/core/maploader.cpp b/source/core/maploader.cpp
index ee6bf0d99..88449a459 100644
--- a/source/core/maploader.cpp
+++ b/source/core/maploader.cpp
@@ -208,7 +208,7 @@ static void SetWallPalV5()
 
 static void ValidateSprite(spritetype& spr)
 {
-	int index = &spr - sprite;
+	int index = int(&spr - sprite);
 	bool bugged = false;
 	if ((unsigned)spr.statnum >= MAXSTATUS)
 	{
diff --git a/source/core/rts.cpp b/source/core/rts.cpp
index ac892f2e0..1754d990f 100644
--- a/source/core/rts.cpp
+++ b/source/core/rts.cpp
@@ -95,7 +95,7 @@ bool RTS_IsInitialized()
 			{
 				FileLump *li = (FileLump*)(RTSFile.Data() + LittleLong(wi->infotableofs));
 				LumpInfo.Resize(numlumps);
-				for(unsigned i = 0; i < numlumps; i++, li++)
+				for(int i = 0; i < numlumps; i++, li++)
 				{
 					LumpInfo[i] = { LittleLong(li->position), LittleLong(li->size), -1 };
 					if (unsigned(LumpInfo[i].position + LumpInfo[i].size) >= RTSFile.Size())
diff --git a/source/core/screenjob.cpp b/source/core/screenjob.cpp
index 5126798b1..f8e905dec 100644
--- a/source/core/screenjob.cpp
+++ b/source/core/screenjob.cpp
@@ -94,7 +94,7 @@ void Job_Init()
 
 static VMFunction* LookupFunction(const char* qname, bool validate = true)
 {
-	int p = strcspn(qname, ".");
+	size_t p = strcspn(qname, ".");
 	if (p == 0) I_Error("Call to undefined function %s", qname);
 	FString clsname(qname, p);
 	FString funcname = qname + p + 1;
diff --git a/source/core/searchpaths.cpp b/source/core/searchpaths.cpp
index 99c974399..194606caa 100644
--- a/source/core/searchpaths.cpp
+++ b/source/core/searchpaths.cpp
@@ -665,7 +665,7 @@ void GetCRC(FileEntry *entry, TArray<FileEntry> &CRCCache)
 		do
 		{
 			b = f.Read(buffer.Data(), buffer.Size());
-			if (b > 0) crcval = AddCRC32(crcval, buffer.Data(), b);
+			if (b > 0) crcval = AddCRC32(crcval, buffer.Data(), unsigned(b));
 		}
 		while (b == buffer.Size());
 		entry->CRCValue = crcval;
diff --git a/source/core/statusbar2.cpp b/source/core/statusbar2.cpp
index cce7f8f90..2844b354d 100644
--- a/source/core/statusbar2.cpp
+++ b/source/core/statusbar2.cpp
@@ -140,7 +140,7 @@ void DBaseStatusBar::PrintLevelStats(FLevelStats &stats)
 {
 	double y;
 	double scale = stats.fontscale * hud_statscale;
-	if (stats.spacing <= 0) stats.spacing = stats.font->GetHeight() * stats.fontscale;
+	if (stats.spacing <= 0) stats.spacing = xs_CRoundToInt(stats.font->GetHeight() * stats.fontscale);
 	double spacing = stats.spacing * hud_statscale;
 	if (stats.screenbottomspace < 0)
 	{
@@ -226,7 +226,7 @@ void DBaseStatusBar::PrintAutomapInfo(FLevelStats& stats, bool forcetextfont)
 	forcetextfont |= am_textfont;
 	double y;
 	double scale = stats.fontscale * (forcetextfont ? *hud_statscale : 1);	// the tiny default font used by all games here cannot be scaled for readability purposes.
-	if (stats.spacing <= 0) stats.spacing = stats.font->GetHeight() * stats.fontscale;
+	if (stats.spacing <= 0) stats.spacing = xs_CRoundToInt(stats.font->GetHeight() * stats.fontscale);
 	double spacing = stats.spacing * (forcetextfont ? *hud_statscale : 1);
 	if (am_nameontop)
 	{
diff --git a/source/libsmackerdec/src/SmackerDecoder.cpp b/source/libsmackerdec/src/SmackerDecoder.cpp
index 7b00caed8..c981d35a6 100644
--- a/source/libsmackerdec/src/SmackerDecoder.cpp
+++ b/source/libsmackerdec/src/SmackerDecoder.cpp
@@ -69,7 +69,7 @@ SmackerHandle Smacker_Open(const char* fileName)
 	classInstances.push_back(newDecoder);
 
 	// get a handle ID
-	newHandle.instanceIndex = classInstances.size() - 1;
+	newHandle.instanceIndex = int(classInstances.size()) - 1;
 
 	// loaded ok, make handle valid
 	newHandle.isValid = true;
@@ -1116,7 +1116,7 @@ void SmackerDecoder::GotoFrame(uint32_t frameNum)
     currentFrame = 0;
     nextPos = firstFrameFilePos;
 
-    for (int i = 0; i < frameNum + 1; i++)
+    for (unsigned i = 0; i < frameNum + 1; i++)
         GetNextFrame();
 }