diff --git a/src/util/externalcommandhelper.cpp b/src/util/externalcommandhelper.cpp
index 9bb01ec..a2ab6da 100644
--- a/src/util/externalcommandhelper.cpp
+++ b/src/util/externalcommandhelper.cpp
@@ -127,15 +127,19 @@ bool ExternalCommandHelper::writeData(QFile& device, const QByteArray& buffer, c
     return true;
 }
 
-/** Creates a new file with given contents.
-    @param fileContents the data that we write
+/** Creates a new fstab file with given contents.
+    @param Contents the data that we write
     @return true on success
 */
-bool ExternalCommandHelper::WriteFstab(const QByteArray& fileContents)
+bool ExternalCommandHelper::WriteFstab(const QByteArray& fstabContents)
 {
     if (!isCallerAuthorized()) {
         return false;
     }
+    if (fstabContents.size() > MiB) {
+        qCritical() << QStringLiteral("/etc/fstab size limit exceeded.");
+        return false;
+    }
     QString fstabPath = QStringLiteral("/etc/fstab");
     QFile fstabFile(fstabPath);
 
@@ -146,7 +150,7 @@ bool ExternalCommandHelper::WriteFstab(const QByteArray& fileContents)
         return false;
     }
 
-    if (fstabFile.write(fileContents) != fileContents.size()) {
+    if (fstabFile.write(fstabContents) != fstabContents.size()) {
         qCritical() << xi18n("Could not write to file <filename>%1</filename>.", fstabPath);
         return false;
     }
diff --git a/src/util/externalcommandhelper.h b/src/util/externalcommandhelper.h
index 0954e8e..e3c6931 100644
--- a/src/util/externalcommandhelper.h
+++ b/src/util/externalcommandhelper.h
@@ -43,7 +43,7 @@ public Q_SLOTS:
                                         const QString& targetDevice, const qint64 targetOffset, const qint64 blockSize);
     Q_SCRIPTABLE QByteArray ReadData(const QString& device, const qint64 offset, const qint64 length);
     Q_SCRIPTABLE bool WriteData(const QByteArray& buffer, const QString& targetDevice, const qint64 targetOffset);
-    Q_SCRIPTABLE bool WriteFstab(const QByteArray& fileContents);
+    Q_SCRIPTABLE bool WriteFstab(const QByteArray& fstabContents);
 
 private:
     bool isCallerAuthorized();