diff --git a/packaging/build_config.sh b/packaging/build_config.sh
index 5ce5fffc3..a8089bf39 100755
--- a/packaging/build_config.sh
+++ b/packaging/build_config.sh
@@ -25,8 +25,8 @@ FFTW_VERSION=fftw-3.3.2
 LIBSAMPLERATE_VERSION=libsamplerate-0.1.8
 LIBYAML_VERSION=yaml-0.1.5
 CHROMAPRINT_VERSION=1.4.3
-QT_SOURCE_URL=https://download.qt.io/archive/qt/4.8/4.8.4/qt-everywhere-opensource-src-4.8.4.tar.gz
-GAIA_VERSION=2.4.6-86-ged433ed
+QT_VERSION=5.15.6
+GAIA_VERSION=2.4.6-108-ge2faf99
 TENSORFLOW_VERSION=2.5.0
 
 
@@ -224,53 +224,56 @@ LIBSAMPLERATE_FLAGS="
 
 QT_FLAGS="
     -no-accessibility
-    -no-webkit
     -no-glib
-    -no-xkb
-    -no-xinput
     -no-fontconfig
-    -no-mitshm
-    -no-xrender
-    -no-xrandr
-    -no-xfixes
-    -no-xcursor
-    -no-xinerama
-    -no-xsync
-    -no-xvideo
-    -no-xshape
     -no-sm
     -no-openvg
     -no-opengl
-    -no-nas-sound
-    -no-gtkstyle
     -no-dbus
     -no-pch
     -no-iconv
     -no-cups
-    -no-nis
     -no-gui
     -no-openssl
     -no-libjpeg
-    -no-libmng
     -no-libpng
-    -no-libtiff
     -no-gif
-    -no-scripttools
-    -no-script
-    -no-javascript-jit
-    -no-svg
-    -no-phonon-backend
-    -no-phonon
-    -no-audio-backend
-    -no-multimedia
-    -no-xmlpatterns
-    -no-qt3support
+
     -qt-zlib
-    -nomake demos
     -nomake examples
     -nomake tools
-    -nomake translations
 "
+# Non-existent flags removed after migration from Qt 4 to Qt 5.15.6
+#-no-webkit
+#-no-xkb
+#-no-xinput
+#-no-mitshm
+#-no-xrender
+#-no-xrandr
+#-no-xfixes
+#-no-xcursor
+#-no-xinerama
+#-no-xsync
+#-no-xvideo
+#-no-xshape
+#-no-nas-sound
+#-no-gtkstyle
+#-no-nis
+#-no-libmng
+#-no-libtiff
+#-no-scripttools
+#-no-script
+#-no-javascript-jit
+#-no-svg
+#-no-phonon-backend
+#-no-phonon
+#-no-audio-backend
+#-no-multimedia
+#-no-xmlpatterns
+#-no-qt3support
+#-nomake demos
+#-nomake translations
+
 
 TENSORFLOW_FLAGS="
     --config=opt
diff --git a/packaging/debian_3rdparty/build_qt.sh b/packaging/debian_3rdparty/build_qt.sh
index 6ea1ec499..ce8b2d44b 100755
--- a/packaging/debian_3rdparty/build_qt.sh
+++ b/packaging/debian_3rdparty/build_qt.sh
@@ -8,12 +8,14 @@ cd tmp
 
 echo "Building qt from $QT_SOURCE_URL"
 
+QT_SHORT_VERSION=${QT_VERSION%.*}
+QT_SOURCE_URL=https://download.qt.io/archive/qt/$QT_SHORT_VERSION/$QT_VERSION/single/qt-everywhere-opensource-src-$QT_VERSION.tar.xz
 QT_FILE=${QT_SOURCE_URL##*/}
+QT_FILE_DIR=qt-everywhere-src-$QT_VERSION
 
 curl -SLO $QT_SOURCE_URL
-
 tar -xf $QT_FILE
-cd $(basename $QT_FILE .tar.gz)
+cd $QT_FILE_DIR
 
 ./configure -prefix $PREFIX -static -opensource -confirm-license $QT_FLAGS