diff --git a/debian/control b/debian/control
index 9c80166..346a72f 100644
--- a/debian/control
+++ b/debian/control
@@ -6,7 +6,7 @@ Build-Depends: cmake (>= 3.24~),
                debhelper-compat (= 13),
                default-libmysqlclient-dev,
                dh-exec,
-               firebird-dev [linux-any],
+               firebird-dev (<< 4.0~) [linux-any],
                libatspi2.0-dev,
                libb2-dev,
                libcups2-dev,
@@ -73,8 +73,8 @@ Build-Depends: cmake (>= 3.24~),
                qt6-base-dev:native <cross>,
                unixodbc-dev,
                zlib1g-dev,
-Build-Depends-Indep: qt6-base-dev (>= 6.4~) <!nodoc>,
-                     qt6-documentation-tools (>= 6.4~) <!nodoc>,
+Build-Depends-Indep: qt6-base-dev (>= 6.6~) <!nodoc>,
+                     qt6-documentation-tools (>= 6.6~) <!nodoc>,
 Standards-Version: 4.6.2
 Section: libs
 Homepage: https://www.qt.io/developers/
diff --git a/debian/rules b/debian/rules
index 03b46ec..c010501 100755
--- a/debian/rules
+++ b/debian/rules
@@ -85,10 +85,6 @@ override_dh_auto_configure:
 
 
 execute_after_dh_auto_install-arch:
-	# Policy § 10.4. Remove this if https://bugs.debian.org/904409 gets fixed.
-	sed -i 's,bin/env perl,bin/perl,' debian/tmp/usr/lib/qt6/libexec/*.pl \
-		debian/tmp/usr/lib/$(DEB_HOST_MULTIARCH)/qt6/mkspecs/features/data/unix/findclasslist.pl
-
 	# Reproducible builds: remove build paths from .prl files
 	sed -i -e '/^QMAKE_PRL_BUILD_DIR/d' debian/tmp/usr/lib/$(DEB_HOST_MULTIARCH)/libQt6*.prl