diff --git a/src/common/engine/serializer.cpp b/src/common/engine/serializer.cpp
index d7b94739b0..ae0ad5ffc5 100644
--- a/src/common/engine/serializer.cpp
+++ b/src/common/engine/serializer.cpp
@@ -762,9 +762,9 @@ FCompressedBuffer FSerializer::GetCompressedOutput()
 	int err;
 
 	stream.next_in = (Bytef *)w->mOutString.GetString();
-	stream.avail_in = buff.mSize;
+	stream.avail_in = (unsigned)buff.mSize;
 	stream.next_out = (Bytef*)compressbuf;
-	stream.avail_out = buff.mSize;
+	stream.avail_out = (unsigned)buff.mSize;
 	stream.zalloc = (alloc_func)0;
 	stream.zfree = (free_func)0;
 	stream.opaque = (voidpf)0;
diff --git a/src/common/fonts/hexfont.cpp b/src/common/fonts/hexfont.cpp
index 6a788c001e..00dbf0830e 100644
--- a/src/common/fonts/hexfont.cpp
+++ b/src/common/fonts/hexfont.cpp
@@ -63,7 +63,7 @@ struct HexDataSource
 		FScanner sc;
 
 		auto data = resf->Read(index);
-		sc.OpenMem("newconsolefont.hex", data.string(), data.size());
+		sc.OpenMem("newconsolefont.hex", data.string(), (int)data.size());
 		sc.SetCMode(true);
 		glyphdata.Push(0);	// ensure that index 0 can be used as 'not present'.
 		while (sc.GetString())
diff --git a/src/common/models/models_iqm.cpp b/src/common/models/models_iqm.cpp
index 429da9b14c..d22c0d9d55 100644
--- a/src/common/models/models_iqm.cpp
+++ b/src/common/models/models_iqm.cpp
@@ -137,7 +137,7 @@ bool IQMModel::Load(const char* path, int lumpnum, const char* buffer, int lengt
 		}
 
 		reader.SeekTo(ofs_anims);
-		for(int i = 0; i < Anims.Size(); i++)
+		for(unsigned i = 0; i < Anims.Size(); i++)
 		{
 			IQMAnim& anim = Anims[i];
 			anim.Name = reader.ReadName(text);
diff --git a/src/common/scripting/core/types.cpp b/src/common/scripting/core/types.cpp
index 1fcd244d8e..1e9302bd4d 100644
--- a/src/common/scripting/core/types.cpp
+++ b/src/common/scripting/core/types.cpp
@@ -2568,7 +2568,7 @@ static void PMapValueWriter(FSerializer &ar, const M *map, const PMap *m)
 					{ // invalid
 						m->ValueType->WriteValue(ar,"invalid",static_cast<const void *>(&p->Value));
 					}
-					else if(p->Key == 0 || p->Key >= TexMan.NumTextures())
+					else if(p->Key == 0 || p->Key >= (unsigned)TexMan.NumTextures())
 					{ // null
 						m->ValueType->WriteValue(ar,"null",static_cast<const void *>(&p->Value));
 					}
@@ -2693,7 +2693,7 @@ static bool PMapValueReader(FSerializer &ar, M *map, const PMap *m)
 						ar.EndObject();
 						return false;
 					}
-					int v = s.ToULong();
+					int v = (int)s.ToULong();
 
 					if (sysCallbacks.RemapTranslation) v = sysCallbacks.RemapTranslation(FTranslationID::fromInt(v)).index();