diff -r 24a506eb97b5 -r 12c329f5524f src/types/IntegerDataTypeReader.h
--- a/src/types/IntegerDataTypeReader.h	Tue Dec 10 19:37:50 2019 +0100
+++ b/src/types/IntegerDataTypeReader.h	Fri Dec 13 22:19:39 2019 +0100
@@ -38,14 +38,14 @@
 using namespace relpipe::reader;
 
 /**
- * Unsigned variable-length integer.
- * ULEB128
+ * Signed variable-length integer.
+ * LEB128
  */
 class IntegerDataTypeReader : public DataTypeReader<integer_t> {
 private:
 
-	uint8_t readNextOctet(std::istream &input) {
-		uint8_t value = input.get();
+	octet_t readNextOctet(std::istream &input) {
+		octet_t value = input.get();
 		if (input.good()) return value;
 		else throw RelpipeReaderException(L"Unable to read next octet of the integer.");
 	}
@@ -64,6 +64,9 @@
 			value += integer_t(octet & 0x7F) << shift;
 			shift += 7;
 		} while (octet >= 128);
+
+		if ((shift < (sizeof (integer_t) * 8)) && (octet & 0x40))
+			value |= (~0 << shift);
 		return value;
 	}