diff --git a/src/m_swap.h b/src/m_swap.h
index f5606e59c3..ddcf8eaf90 100644
--- a/src/m_swap.h
+++ b/src/m_swap.h
@@ -46,6 +46,11 @@ inline short LittleShort(int x)
 	return OSSwapLittleToHostInt16((uint16_t)x);
 }
 
+inline unsigned short LittleShort(unsigned int x)
+{
+	return OSSwapLittleToHostInt16((uint16_t)x);
+}
+
 inline int LittleLong(int x)
 {
 	return OSSwapLittleToHostInt32((uint32_t)x);
@@ -56,6 +61,16 @@ inline unsigned int LittleLong(unsigned int x)
 	return OSSwapLittleToHostInt32(x);
 }
 
+inline int LittleLong(long x)
+{
+	return OSSwapLittleToHostInt32((uint32_t)x);
+}
+
+inline unsigned int LittleLong(unsigned long x)
+{
+	return OSSwapLittleToHostInt32((uint32_t)x);
+}
+
 inline short BigShort(short x)
 {
 	return (short)OSSwapBigToHostInt16((uint16_t)x);
diff --git a/src/serializer.cpp b/src/serializer.cpp
index a23459ced0..445a3b22b0 100644
--- a/src/serializer.cpp
+++ b/src/serializer.cpp
@@ -1294,7 +1294,7 @@ FSerializer &SerializePointer(FSerializer &arc, const char *key, T *&value, T **
 	assert(base != nullptr);
 	if (arc.isReading() || !arc.w->inObject() || defval == nullptr || value != *defval)
 	{
-		ptrdiff_t vv = value == nullptr ? -1 : value - base;
+		int64_t vv = value == nullptr ? -1 : value - base;
 		Serialize(arc, key, vv, nullptr);
 		value = vv < 0 ? nullptr : base + vv;
 	}