diff --git a/daemon/backends/upower/backlighthelper.h b/daemon/backends/upower/backlighthelper.h
--- a/daemon/backends/upower/backlighthelper.h
+++ b/daemon/backends/upower/backlighthelper.h
@@ -47,15 +47,8 @@
      */
     void initUsingBacklightType();
 
-    /**
-     * FreeBSD (and other BSDs) can control backlight via acpi_video(4)
-     */
-    void initUsingSysctl();
-
     bool m_isSupported = false;
     QString m_dirname;
-    QString m_sysctlDevice;
-    QList<int> m_sysctlBrightnessLevels;
 };
 
 #endif // BACKLIGHTHELPER_H
diff --git a/daemon/backends/upower/backlighthelper.cpp b/daemon/backends/upower/backlighthelper.cpp
--- a/daemon/backends/upower/backlighthelper.cpp
+++ b/daemon/backends/upower/backlighthelper.cpp
@@ -28,17 +28,6 @@
 
 #include <sys/utsname.h>
 
-#ifdef Q_OS_FREEBSD
-#define USE_SYSCTL
-#endif
-
-#ifdef USE_SYSCTL
-#include <sys/types.h>
-#include <sys/sysctl.h>
-
-#define HAS_SYSCTL(n) (sysctlbyname(n, NULL, NULL, NULL, 0) == 0)
-#endif
-
 #define BACKLIGHT_SYSFS_PATH "/sys/class/backlight/"
 #define LED_SYSFS_PATH "/sys/class/leds/"
 
@@ -52,12 +41,8 @@
     initUsingBacklightType();
 
     if (m_dirname.isEmpty()) {
-        initUsingSysctl();
-
-        if (m_sysctlDevice.isEmpty() || m_sysctlBrightnessLevels.isEmpty()) {
-            qCWarning(POWERDEVIL) << "no kernel backlight interface found";
-            return;
-        }
+        qCWarning(POWERDEVIL) << "no kernel backlight interface found";
+        return;
     }
 
     m_isSupported = true;
@@ -134,60 +119,6 @@
 
 }
 
-void BacklightHelper::initUsingSysctl()
-{
-#ifdef USE_SYSCTL
-    /*
-     * lcd0 is, in theory, the correct device, but some vendors have custom ACPI implementations
-     * which cannot be interpreted. In that case, devices should be reported as "out", but
-     * FreeBSD doesn't care (yet), so they can appear as any other type. Let's search for the first
-     * device with brightness management, then.
-     */
-    QStringList types;
-    types << QStringLiteral("lcd") << QStringLiteral("out") << QStringLiteral("crt") << QStringLiteral("tv") << QStringLiteral("ext");
-    Q_FOREACH (const QString &type, types) {
-        for (int i = 0; m_sysctlDevice.isEmpty(); i++) {
-            QString device = QStringLiteral("%1%2").arg(type, QString::number(i));
-            // We don't care about the value, we only want the sysctl to be there.
-            if (!HAS_SYSCTL(qPrintable(QStringLiteral("hw.acpi.video.%1.active").arg(device)))) {
-                break;
-            }
-            if (HAS_SYSCTL(qPrintable(QStringLiteral("hw.acpi.video.%1.brightness").arg(device))) &&
-                HAS_SYSCTL(qPrintable(QStringLiteral("hw.acpi.video.%1.levels").arg(device)))) {
-                m_sysctlDevice = device;
-                break;
-            }
-        }
-    }
-
-    if (m_sysctlDevice.isEmpty()) {
-        return;
-    }
-
-    size_t len;
-    if (sysctlbyname(qPrintable(QStringLiteral("hw.acpi.video.%1.levels").arg(m_sysctlDevice)), NULL, &len, NULL, 0) != 0 ||
-        len == 0) {
-        return;
-    }
-    int *levels = (int *)malloc(len);
-    if (!levels) {
-        return;
-    }
-    if (sysctlbyname(qPrintable(QString("hw.acpi.video.%1.levels").arg(m_sysctlDevice)), levels, &len, NULL, 0) != 0) {
-        free(levels);
-        return;
-    }
-    // acpi_video(4) supports only some predefined brightness levels.
-    int nlevels = len / sizeof(int);
-    for (int i = 0; i < nlevels; i++) {
-        m_sysctlBrightnessLevels << levels[i];
-    }
-    free(levels);
-    // Sorting helps when finding max value and when scanning for the nearest level in setbrightness().
-    qSort(m_sysctlBrightnessLevels.begin(), m_sysctlBrightnessLevels.end());
-#endif
-}
-
 ActionReply BacklightHelper::brightness(const QVariantMap &args)
 {
     Q_UNUSED(args);
@@ -202,13 +133,6 @@
     // current brightness
     int brightness;
 
-#ifdef USE_SYSCTL
-    size_t len = sizeof(int);
-    if (sysctlbyname(qPrintable(QStringLiteral("hw.acpi.video.%1.brightness").arg(m_sysctlDevice)), &brightness, &len, NULL, 0) != 0) {
-        reply = ActionReply::HelperErrorReply();
-        return reply;
-    }
-#else
     QFile file(m_dirname + "/brightness");
     if (!file.open(QIODevice::ReadOnly)) {
         reply = ActionReply(ActionReply::HelperErrorType);
@@ -220,7 +144,6 @@
     QTextStream stream(&file);
     stream >> brightness;
     file.close();
-#endif
 
     //qCDebug(POWERDEVIL) << "brightness:" << brightness;
     reply.addData("brightness", brightness);
@@ -242,31 +165,6 @@
 
     //qCDebug(POWERDEVIL) << "setting brightness:" << actual_brightness;
 
-#ifdef USE_SYSCTL
-    int actual_level = -1;
-    int d1 = 101;
-    // Search for the nearest level.
-    Q_FOREACH (int level, m_sysctlBrightnessLevels) {
-        int d2 = qAbs(level - actual_brightness);
-        /*
-         * The list is sorted, so we break when it starts diverging. There may be repeated values,
-         * so we keep going on equal gap (e.g., value = 7.5, levels = 0 0 10 ...: we don't break at
-         * the second '0' so we can get to the '10'). This also means that the value will always
-         * round off to the bigger level when in the middle (e.g., value = 5, levels = 0 10 ...:
-         * value rounds off to 10).
-         */
-        if (d2 > d1) {
-            break;
-        }
-        actual_level = level;
-        d1 = d2;
-    }
-    size_t len = sizeof(int);
-    if (sysctlbyname(qPrintable(QStringLiteral("hw.acpi.video.%1.brightness").arg(m_sysctlDevice)), NULL, NULL, &actual_level, len) != 0) {
-        reply = ActionReply::HelperErrorReply();
-        return reply;
-    }
-#else
     QFile file(m_dirname + QLatin1String("/brightness"));
     if (!file.open(QIODevice::WriteOnly)) {
         reply = ActionReply::HelperErrorReply();
@@ -283,7 +181,6 @@
 //         reply.setErrorCode(file.error());
         qCWarning(POWERDEVIL) << "writing brightness failed with error code " << file.error() << file.errorString();
     }
-#endif
     return reply;
 }
 
@@ -317,9 +214,6 @@
     // maximum brightness
     int max_brightness;
 
-#ifdef USE_SYSCTL
-    max_brightness = m_sysctlBrightnessLevels.last();
-#else
     QFile file(m_dirname + QLatin1String("/max_brightness"));
     if (!file.open(QIODevice::ReadOnly)) {
         reply = ActionReply::HelperErrorReply();
@@ -331,7 +225,6 @@
     QTextStream stream(&file);
     stream >> max_brightness;
     file.close();
-#endif
 
     //qCDebug(POWERDEVIL) << "max brightness:" << max_brightness;