diff --git a/src/data/itnparser.cpp b/src/data/itnparser.cpp
index 13ceb802..75519c11 100644
--- a/src/data/itnparser.cpp
+++ b/src/data/itnparser.cpp
@@ -18,7 +18,7 @@ bool ITNParser::parse(QFile *file, QList<TrackData> &tracks,
 	_errorString.clear();
 
 	while (!file->atEnd()) {
-		ba = file->readLine();
+		ba = file->readLine(4096);
 
 		QList<QByteArray> fields(ba.split('|'));
 		if (fields.size() < 4) {
diff --git a/src/data/oziparsers.cpp b/src/data/oziparsers.cpp
index a56bd398..8f1e7ab1 100644
--- a/src/data/oziparsers.cpp
+++ b/src/data/oziparsers.cpp
@@ -45,7 +45,7 @@ bool PLTParser::parse(QFile *file, QList<TrackData> &tracks,
 	SegmentData &segment = track.last();
 
 	while (!file->atEnd()) {
-		QByteArray line = file->readLine();
+		QByteArray line = file->readLine(4096);
 
 		if (_errorLine == 1) {
 			QString fileType(QString::fromUtf8(line).trimmed());
@@ -133,7 +133,7 @@ bool RTEParser::parse(QFile *file, QList<TrackData> &tracks,
 
 
 	while (!file->atEnd()) {
-		QByteArray line = file->readLine();
+		QByteArray line = file->readLine(4096);
 
 		if (_errorLine == 1) {
 			QString fileType(QString::fromUtf8(line).trimmed());
@@ -233,7 +233,7 @@ bool WPTParser::parse(QFile *file, QList<TrackData> &tracks,
 	_errorString.clear();
 
 	while (!file->atEnd()) {
-		QByteArray line = file->readLine();
+		QByteArray line = file->readLine(4096);
 
 		if (_errorLine == 1) {
 			QString fileType(QString::fromUtf8(line).trimmed());
diff --git a/src/data/twonavparser.cpp b/src/data/twonavparser.cpp
index d1914a70..76c91c0d 100644
--- a/src/data/twonavparser.cpp
+++ b/src/data/twonavparser.cpp
@@ -90,7 +90,7 @@ bool TwoNavParser::parse(QFile *file, QList<TrackData> &tracks,
 	}
 
 	while (!file->atEnd()) {
-		QByteArray line(file->readLine().trimmed());
+		QByteArray line(file->readLine(4096).trimmed());
 		if (!line.size())
 			continue;
 
diff --git a/src/map/ellipsoid.cpp b/src/map/ellipsoid.cpp
index 28b51310..8b71b96a 100644
--- a/src/map/ellipsoid.cpp
+++ b/src/map/ellipsoid.cpp
@@ -45,7 +45,7 @@ void Ellipsoid::loadList(const QString &path)
 	while (!file.atEnd()) {
 		ln++;
 
-		QByteArray line = file.readLine();
+		QByteArray line = file.readLine(4096);
 		QList<QByteArray> list = line.split(',');
 		if (list.size() != 4) {
 			qWarning("%s: %d: Format error", qPrintable(path), ln);
diff --git a/src/map/gcs.cpp b/src/map/gcs.cpp
index 3b0bcd89..ed2abf30 100644
--- a/src/map/gcs.cpp
+++ b/src/map/gcs.cpp
@@ -104,7 +104,7 @@ void GCS::loadList(const QString &path)
 	while (!file.atEnd()) {
 		ln++;
 
-		QByteArray line = file.readLine();
+		QByteArray line = file.readLine(4096);
 		QList<QByteArray> list = line.split(',');
 		if (list.size() != 14) {
 			qWarning("%s:%d: Format error", qPrintable(path), ln);
diff --git a/src/map/mapfile.cpp b/src/map/mapfile.cpp
index 129f9d15..fc21f1ce 100644
--- a/src/map/mapfile.cpp
+++ b/src/map/mapfile.cpp
@@ -24,7 +24,7 @@ int MapFile::parse(QIODevice &device, QList<CalibrationPoint> &points,
 
 
 	while (!device.atEnd()) {
-		QByteArray line = device.readLine();
+		QByteArray line = device.readLine(4096);
 
 		if (ln == 1) {
 			QString fileType(QString::fromUtf8(line).trimmed());
diff --git a/src/map/pcs.cpp b/src/map/pcs.cpp
index 7910bed7..e8ff8bf8 100644
--- a/src/map/pcs.cpp
+++ b/src/map/pcs.cpp
@@ -151,7 +151,7 @@ void PCS::loadList(const QString &path)
 	while (!file.atEnd()) {
 		ln++;
 
-		QByteArray line = file.readLine();
+		QByteArray line = file.readLine(4096);
 		QList<QByteArray> list = line.split(',');
 		if (list.size() != 28) {
 			qWarning("%s:%d: Format error", qPrintable(path), ln);
diff --git a/src/map/tar.cpp b/src/map/tar.cpp
index c56366f7..0ed8e1d9 100644
--- a/src/map/tar.cpp
+++ b/src/map/tar.cpp
@@ -93,7 +93,7 @@ bool Tar::loadTmi(const QString &path)
 		return false;
 
 	while (!file.atEnd()) {
-		QByteArray line = file.readLine();
+		QByteArray line = file.readLine(4096);
 		int pos = line.indexOf(':');
 		if (line.size() < 10 || pos < 7 || !line.startsWith("block")) {
 			qWarning("%s:%d: syntax error", qPrintable(path), ln);
diff --git a/src/map/wldfile.cpp b/src/map/wldfile.cpp
index 56752402..04dfd978 100644
--- a/src/map/wldfile.cpp
+++ b/src/map/wldfile.cpp
@@ -13,7 +13,7 @@ WLDFile::WLDFile(const QString &fileName)
 	}
 
 	for (int i = 0; i < 6; i++) {
-		QByteArray line(file.readLine().trimmed());
+		QByteArray line(file.readLine(128).trimmed());
 		val[i] = line.toDouble(&ok);
 		if (!ok) {
 			_errorString = line + ": invalid parameter";