diff --git a/uppsrc/Core/Algo.h b/uppsrc/Core/Algo.h
index eb3124dcb..edd66bca7 100644
--- a/uppsrc/Core/Algo.h
+++ b/uppsrc/Core/Algo.h
@@ -1000,7 +1000,7 @@ template <class II, class VI, class K, class Less>
 inline void __IndexSort(II begin, II end, VI pair, const Less& less, const K *)
 {
 	Sort(IndexSortIterator<II, VI, K>(begin, pair),
-		IndexSortIterator<II, VI, K>(end, pair + (end - begin)),
+		IndexSortIterator<II, VI, K>(end, pair + (int)(ptrdiff_t)(end - begin)),
 		less);
 }
 
diff --git a/uppsrc/Geom/polyalg.cpp b/uppsrc/Geom/polyalg.cpp
index 2d4aa64d8..7395b3735 100644
--- a/uppsrc/Geom/polyalg.cpp
+++ b/uppsrc/Geom/polyalg.cpp
@@ -506,7 +506,7 @@ void PolygonIterator<T>::Add(typename PIUtils<T>::ConstIterator vertices, int ve
 					ue--;
 			}
 			typename PIUtils<T>::PointList& seg1 = segments.Add();
-			seg1.SetCount(degen1 ? 2 : ue - ub + 1 + (ue > ub ? 0 : *counts));
+			seg1.SetCount(degen1 ? 2 : (int)(ue - ub) + 1 + (ue > ub ? 0 : *counts));
 			ASSERT(seg1.GetCount() >= 2);
 			ASSERT(ub != e);
 			typename PIUtils<T>::Iterator sp = seg1.End();
@@ -575,7 +575,7 @@ void PolygonIterator<T>::Add(typename PIUtils<T>::ConstIterator vertices, int ve
 					ue--;
 			}
 			typename PIUtils<T>::PointList& seg2 = segments.Add();
-			seg2.SetCount(degen2 ? 2 : ue - ub + 1 + (ue > ub ? 0 : *counts));
+			seg2.SetCount(degen2 ? 2 : (int)(ue - ub) + 1 + (ue > ub ? 0 : *counts));
 			ASSERT(seg2.GetCount() >= 2);
 			sp = seg2.Begin();
 			if(degen2)
@@ -965,7 +965,7 @@ void PolygonIterator<T>::Flush(int index, T ypos)
 	typename PIUtils<T>::ConstIterator qb = q.done.Begin();
 	if(*qb == p.done[0] && qb < qe)
 		qb++;
-	out_vertices.SetCountR(out_vertices.GetCount() + (qe - qb));
+	out_vertices.SetCountR(out_vertices.GetCount() + (int)(qe - qb));
 	typename PIUtils<T>::Iterator out = out_vertices.End();
 	while(qb < qe)
 		*--out = *qb++;
diff --git a/uppsrc/plugin/dbf/dbf.cpp b/uppsrc/plugin/dbf/dbf.cpp
index c4b3dfac5..befd0c7c0 100644
--- a/uppsrc/plugin/dbf/dbf.cpp
+++ b/uppsrc/plugin/dbf/dbf.cpp
@@ -125,7 +125,7 @@ DbfStream::Field::Field(const char *_name, char type, byte width, byte decimal)
 {
 	if(_name) {
 		const char *p = reinterpret_cast<const char *>(memchr(_name, 0, 11));
-		name = String(_name, p ? p - _name : 11);
+		name = String(_name, p ? (int)(p - _name) : 11);
 	}
 	name = ToUpper(name);
 }
@@ -604,7 +604,7 @@ bool DbfStream::Fetch(int row)
 
 	dbf.Seek(data_offset + row * record.GetCount());
 	byte *p = record.Begin(), *e = record.End();
-	int count = dbf.Get(p, e - p);
+	int count = dbf.Get(p, (int)(e - p));
 	if(count < record.GetCount())
 		memset(p + count, ' ', record.GetCount() - count);
 	if(count <= 0 || (*p != ' ' && *p != 0)) {
@@ -750,7 +750,7 @@ void DbfStream::DumpData(Stream& stream)
 	int i;
 	for(i = 0; i < fields.GetCount(); i++) {
 		const Field& field = GetField(i);
-		int width = max<int>(field.width, strlen(field.name));
+		int width = max<int>(field.width, (int)strlen(field.name));
 		switch(field.type) {
 		case 'D': width = max(width, 10); break;
 		}
@@ -843,7 +843,7 @@ Value DbfStream::GetItemString(int i) const
 		p++;
 	while(e > p && e[-1] == ' ')
 		e--;
-	String s(p, e - p);
+	String s(p, (int)(e - p));
 	if(charset == GetDefaultCharset())
 		return s;
 	return ToUnicode(s, charset);
@@ -920,8 +920,8 @@ Value DbfStream::GetItemMemo(int i, bool binary) const
 					return Value();
 				if(!binary) {
 					byte *p;
-					if(p = (byte *)memchr(buffer, '\0', len)) len = p - buffer;
-					if(p = (byte *)memchr(buffer, '\x1A', len)) len = p - buffer;
+					if(p = (byte *)memchr(buffer, '\0', len)) len = (unsigned)(p - buffer);
+					if(p = (byte *)memchr(buffer, '\x1A', len)) len = (unsigned)(p - buffer);
 				}
 				out = String(buffer, len);
 			}
@@ -936,7 +936,7 @@ Value DbfStream::GetItemMemo(int i, bool binary) const
 							eof = true;
 							break;
 						}
-					int l = e - buffer;
+					int l = (int)(e - buffer);
 					if(!eof && l > dbt_block_size) {
 						dbt.SeekCur(dbt_block_size - l);
 						e = buffer + l;