diff --git a/debian/changelog b/debian/changelog
index f19637b5d..7584561bd 100644
--- a/debian/changelog
+++ b/debian/changelog
@@ -161,6 +161,14 @@ yunohost (11.0.2) testing; urgency=low
 
  -- Alexandre Aubin <alex.aubin@mailoo.org>  Wed, 19 Jan 2022 20:52:39 +0100
 
+yunohost (4.4.2.4) stable; urgency=low
+
+  - [fix] bullseye migration: trash pip freeze stderr because it's confusing users ... (e68fc821)
+  - [fix] bullseye migration: add a check that there's at least 70MB available in /boot ... (02fcbd97)
+  - [fix] bullseye migration: better detection mechanism for the libc6 / libgcc hell issue (633a1fbf)
+
+ -- Alexandre Aubin <alex.aubin@mailoo.org>  Sun, 14 Aug 2022 18:18:13 +0200
+
 yunohost (4.4.2.3) stable; urgency=low
 
   - [fix] bullseye migration: add fix for stupid dnsmasq not picking new init script  (origin/dev, origin/HEAD, dev)
diff --git a/src/migrations/0021_migrate_to_bullseye.py b/src/migrations/0021_migrate_to_bullseye.py
index 5d624c01a..c7474a926 100644
--- a/src/migrations/0021_migrate_to_bullseye.py
+++ b/src/migrations/0021_migrate_to_bullseye.py
@@ -66,7 +66,7 @@ def _backup_pip_freeze_for_python_app_venvs():
     venvs = _get_all_venvs("/opt/") + _get_all_venvs("/var/www/")
     for venv in venvs:
         # Generate a requirements file from venv
-        os.system(f"{venv}/bin/pip freeze > {venv}{VENV_REQUIREMENTS_SUFFIX}")
+        os.system(f"{venv}/bin/pip freeze > {venv}{VENV_REQUIREMENTS_SUFFIX} 2>/dev/null")
 
 
 class MyMigration(Migration):
@@ -201,15 +201,8 @@ class MyMigration(Migration):
         # Another boring fix for the super annoying libc6-dev: Breaks libgcc-8-dev
         # https://forum.yunohost.org/t/20617
         #
-        if (
-            os.system(
-                "grep -A10 'ynh-deps' /var/lib/dpkg/status | grep -q 'Depends:.*build-essential'"
-            )
-            == 0
-        ):
-            logger.info(
-                "Attempting to fix the build-essential / libc6-dev / libgcc-8-dev hell ..."
-            )
+        if os.sytem("dpkg --list | grep '^ii' | grep -q ' libgcc-8-dev '") == 0 and os.system("LC_ALL=C apt policy libgcc-8-dev | grep Candidate | grep -q rpi"):
+            logger.info("Attempting to fix the build-essential / libc6-dev / libgcc-8-dev hell ...")
             os.system("cp /var/lib/dpkg/status /root/dpkg_status.bkp")
             # This removes the dependency to build-essential from $app-ynh-deps
             os.system(
@@ -386,6 +379,9 @@ class MyMigration(Migration):
         if free_space_in_directory("/var/") / (1024**3) < 1.0:
             raise YunohostError("migration_0021_not_enough_free_space")
 
+        if free_space_in_directory("/boot/") / (70**3) < 1.0:
+            raise YunohostError("/boot/ has less than 70MB available. This will probably trigger a crash during the upgrade because a new kernel needs to be installed. Please look for advice on the forum on how to remove old unused kernels to free some space in /boot/.", raw_msg=True)
+
         # Check system is up to date
         # (but we don't if 'bullseye' is already in the sources.list ...
         # which means maybe a previous upgrade crashed and we're re-running it)