diff --git a/cpp/BitBuffer.cpp b/cpp/BitBuffer.cpp
index 8f94eb4..058b5d3 100644
--- a/cpp/BitBuffer.cpp
+++ b/cpp/BitBuffer.cpp
@@ -37,12 +37,12 @@ int BitBuffer::getBitLength() const {
 }
 
 
-std::vector<uint8_t> BitBuffer::getBytes() const {
+std::vector<std::uint8_t> BitBuffer::getBytes() const {
 	return data;
 }
 
 
-void BitBuffer::appendBits(uint32_t val, int len) {
+void BitBuffer::appendBits(std::uint32_t val, int len) {
 	if (len < 0 || len > 32 || (len < 32 && (val >> len) != 0))
 		throw "Value out of range";
 	if (len > INT_MAX - bitLength)
diff --git a/cpp/QrSegment.cpp b/cpp/QrSegment.cpp
index cd514d5..c2a4667 100644
--- a/cpp/QrSegment.cpp
+++ b/cpp/QrSegment.cpp
@@ -137,7 +137,7 @@ int QrSegment::getTotalBits(const std::vector<QrSegment> &segs, int version) {
 	if (version < 1 || version > 40)
 		throw "Version number out of range";
 	int result = 0;
-	for (size_t i = 0; i < segs.size(); i++) {
+	for (std::size_t i = 0; i < segs.size(); i++) {
 		const QrSegment &seg(segs.at(i));
 		int ccbits = seg.mode.numCharCountBits(version);
 		// Fail if segment length value doesn't fit in the length field's bit-width