diff --git a/Justfile b/Justfile
index a33e9640f..13d0eca12 100644
--- a/Justfile
+++ b/Justfile
@@ -138,7 +138,7 @@ test-composefs bootloader filesystem boot_type seal_state:
                 --filesystem={{filesystem}} \
                 --seal-state={{seal_state}} \
                 --boot-type={{boot_type}} \
-                $(if [ "{{boot_type}}" = "uki" ]; then echo "readonly"; else echo "integration"; fi)
+                $(if [ "{{boot_type}}" = "uki" ]; then echo "readonly composefs-upgrade"; else echo "integration"; fi)
 
 # Run cargo fmt and clippy checks in container
 [group('core')]
@@ -314,7 +314,24 @@ _keygen:
     ./hack/generate-secureboot-keys
 
 _build-upgrade-image:
-    cat tmt/tests/Dockerfile.upgrade | podman build -t {{upgrade_img}} --from={{base_img}} -
+    #!/bin/bash
+    set -xeuo pipefail
+    # Secrets are always available (test-tmt depends on build which runs _keygen).
+    # Extra capabilities are only needed for UKI builds (composefs + fuse).
+    extra_args=()
+    if [ "{{boot_type}}" = "uki" ]; then
+        extra_args+=(--cap-add=all --security-opt=label=type:container_runtime_t --device /dev/fuse)
+    fi
+    podman build \
+        --build-arg boot_type={{boot_type}} \
+        --build-arg seal_state={{seal_state}} \
+        --build-arg filesystem={{filesystem}} \
+        --secret=id=secureboot_key,src=target/test-secureboot/db.key \
+        --secret=id=secureboot_cert,src=target/test-secureboot/db.crt \
+        "${extra_args[@]}" \
+        -t {{upgrade_img}} \
+        -f tmt/tests/Dockerfile.upgrade \
+        .
 
 # Copy an image from user podman storage to root's podman storage
 # This allows building as regular user then running privileged tests
diff --git a/tmt/plans/integration.fmf b/tmt/plans/integration.fmf
index ae6374690..a695fd9c8 100644
--- a/tmt/plans/integration.fmf
+++ b/tmt/plans/integration.fmf
@@ -182,8 +182,15 @@ execute:
     test:
       - /tmt/tests/tests/test-34-user-agent
 
+/plan-35-upgrade-preflight-disk-check:
+  summary: Verify pre-flight disk space check rejects images with inflated layer sizes
+  discover:
+    how: fmf
+    test:
+      - /tmt/tests/tests/test-35-upgrade-preflight-disk-check
+
 /plan-36-rollback:
-  summary: Test bootc rollback functionality through image switch and rollback cycle
+  summary: Test bootc rollback functionality
   discover:
     how: fmf
     test:
@@ -202,4 +209,12 @@ execute:
     how: fmf
     test:
       - /tmt/tests/tests/test-38-install-bootloader-none
+
+/plan-39-composefs-upgrade:
+  summary: Test composefs upgrade with pre-built (optionally sealed) image
+  discover:
+    how: fmf
+    test:
+      - /tmt/tests/tests/test-39-composefs-upgrade
+  extra-try_bind_storage: true
 # END GENERATED PLANS
diff --git a/tmt/tests/Dockerfile.upgrade b/tmt/tests/Dockerfile.upgrade
index a9e36ba50..9019dcdfa 100644
--- a/tmt/tests/Dockerfile.upgrade
+++ b/tmt/tests/Dockerfile.upgrade
@@ -1,3 +1,62 @@
-# Just creates a file as a new layer for a synthetic upgrade test
-FROM localhost/bootc
-RUN touch --reference=/usr/bin/bash /usr/share/testing-bootc-upgrade-apply
+# Creates a synthetic upgrade image for testing.
+# For non-UKI builds, this just adds a marker file on top of localhost/bootc.
+# For UKI builds (boot_type=uki), the image is re-sealed with a new composefs
+# digest and (optionally signed) UKI.
+#
+# Build secrets required (for sealed builds):
+#   secureboot_key, secureboot_cert
+ARG boot_type=bls
+ARG seal_state=unsealed
+ARG filesystem=ext4
+
+# Capture contrib/packaging scripts for use in later stages
+FROM scratch AS packaging
+COPY contrib/packaging /
+
+# Create the upgrade content (a simple marker file).
+# For UKI builds, we also remove the existing UKI so that seal-uki can
+# regenerate it with the correct composefs digest for this derived image.
+FROM localhost/bootc AS upgrade-base
+ARG boot_type
+RUN touch --reference=/usr/bin/bash /usr/share/testing-bootc-upgrade-apply && \
+    if test "${boot_type}" = "uki"; then rm -rf /boot/EFI/Linux/*.efi; fi
+
+# Tools for sealing (only meaningfully used for UKI builds)
+FROM localhost/bootc AS tools
+RUN --mount=type=tmpfs,target=/run --mount=type=tmpfs,target=/tmp \
+    --mount=type=bind,from=packaging,src=/,target=/run/packaging \
+    /run/packaging/initialize-sealing-tools
+
+# Generate a sealed UKI for the upgrade image.
+# bootc is already installed in localhost/bootc (our tools base); the
+# container ukify command it provides is needed for seal-uki.
+FROM tools AS sealed-upgrade-uki
+ARG boot_type seal_state filesystem
+RUN --network=none --mount=type=tmpfs,target=/run --mount=type=tmpfs,target=/tmp \
+    --mount=type=secret,id=secureboot_key \
+    --mount=type=secret,id=secureboot_cert \
+    --mount=type=bind,from=packaging,src=/,target=/run/packaging \
+    --mount=type=bind,from=upgrade-base,src=/,target=/run/target <<EORUN
+set -xeuo pipefail
+
+allow_missing_verity=false
+if [[ $filesystem == "xfs" ]]; then
+    allow_missing_verity=true
+fi
+
+if test "${boot_type}" = "uki"; then
+  /run/packaging/seal-uki /run/target /out /run/secrets $allow_missing_verity $seal_state
+fi
+EORUN
+
+# Final stage: the upgrade image, optionally with a re-sealed UKI
+FROM upgrade-base
+ARG boot_type
+RUN --network=none --mount=type=tmpfs,target=/run --mount=type=tmpfs,target=/tmp \
+    --mount=type=bind,from=packaging,src=/,target=/run/packaging \
+    --mount=type=bind,from=sealed-upgrade-uki,src=/,target=/run/sealed-uki <<EORUN
+set -xeuo pipefail
+if test "${boot_type}" = "uki"; then
+  /run/packaging/finalize-uki /run/sealed-uki/out
+fi
+EORUN
diff --git a/tmt/tests/booted/test-composefs-upgrade.nu b/tmt/tests/booted/test-composefs-upgrade.nu
new file mode 100644
index 000000000..edacd6b37
--- /dev/null
+++ b/tmt/tests/booted/test-composefs-upgrade.nu
@@ -0,0 +1,111 @@
+# number: 39
+# extra:
+#   try_bind_storage: true
+# tmt:
+#   summary: Test composefs upgrade with pre-built (optionally sealed) image
+#   duration: 30m
+#
+# This test verifies that upgrading a composefs system works correctly,
+# including sealed UKI images. The upgrade image is pre-built on the host
+# with proper sealing and made available via bind-storage-ro.
+#
+use std assert
+use tap.nu
+
+bootc status
+journalctl --list-boots
+
+let st = bootc status --json | from json
+let booted = $st.status.booted.image
+let is_composefs = (tap is_composefs)
+
+# This test only makes sense for composefs
+if not $is_composefs {
+    tap begin "composefs upgrade (skipped - not composefs)"
+    print "# SKIP: not running on composefs"
+    tap ok
+    exit 0
+}
+
+def upgrade_image [] {
+    $env.BOOTC_upgrade_image? | default "localhost/bootc-upgrade"
+}
+
+# First boot: save the original verity digest, then switch to the upgrade image
+def first_boot [] {
+    tap begin "composefs upgrade with pre-built image"
+
+    # Save the original verity so we can check for two UKIs after upgrade
+    $st.status.booted.composefs.verity | save /var/original-verity
+
+    let img = (upgrade_image)
+    print $"Switching to upgrade image: ($img)"
+
+    # The upgrade image should be available via host container storage
+    # (passed through --bind-storage-ro by bcvk)
+    bootc switch --transport containers-storage $img
+    tmt-reboot
+}
+
+# Second boot: verify the upgrade succeeded and both UKIs exist
+def second_boot [] {
+    print "Verifying composefs upgrade"
+
+    # Verify we booted from the upgrade image
+    let img = (upgrade_image)
+    assert equal $booted.image.transport containers-storage
+    assert equal $booted.image.image $img
+
+    # Verify composefs is still active after the upgrade
+    assert (tap is_composefs) "composefs should still be active after upgrade"
+
+    # Verify the upgrade marker file exists
+    assert ("/usr/share/testing-bootc-upgrade-apply" | path exists) "upgrade marker file should exist"
+
+    # Verify composefs properties are preserved after the upgrade
+    let composefs_info = $st.status.booted.composefs
+    print $"composefs info: ($composefs_info)"
+
+    # Verify there is a valid verity digest (composefs was properly deployed)
+    assert (($composefs_info.verity | str length) > 0) "composefs verity digest should be present"
+
+    # For UKI boot type, verify both the original and upgrade UKIs exist on the ESP
+    if ($composefs_info.bootType | str downcase) == "uki" {
+        let bootloader = ($composefs_info.bootloader | str downcase)
+
+        # UKIs are stored in EFI/Linux/bootc/ on the ESP
+        let boot_dir = if $bootloader == "systemd" {
+            mkdir /var/tmp/efi
+            mount /dev/vda2 /var/tmp/efi
+            "/var/tmp/efi/EFI/Linux/bootc"
+        } else {
+            "/sysroot/boot/EFI/Linux/bootc"
+        }
+
+        let original_verity = (open /var/original-verity | str trim)
+        let upgrade_verity = $composefs_info.verity
+
+        print $"boot_dir: ($boot_dir)"
+        print $"original verity: ($original_verity)"
+        print $"upgrade verity: ($upgrade_verity)"
+
+        # The two verities must differ since the upgrade image has different content
+        assert ($original_verity != $upgrade_verity) "upgrade should produce a different verity digest"
+
+        # There should be two .efi UKI files on the ESP: one for the booted
+        # deployment (upgrade) and one for the rollback (original)
+        let efi_files = (glob $"($boot_dir)/*.efi")
+        print $"EFI files: ($efi_files)"
+        assert ((($efi_files | length) >= 2)) $"expected at least 2 UKIs on ESP, found ($efi_files | length)"
+    }
+
+    tap ok
+}
+
+def main [] {
+    match $env.TMT_REBOOT_COUNT? {
+        null | "0" => first_boot,
+        "1" => second_boot,
+        $o => { error make { msg: $"Invalid TMT_REBOOT_COUNT ($o)" } },
+    }
+}
diff --git a/tmt/tests/tests.fmf b/tmt/tests/tests.fmf
index 851d6b293..d9a3e7de6 100644
--- a/tmt/tests/tests.fmf
+++ b/tmt/tests/tests.fmf
@@ -104,11 +104,11 @@
 
 /test-35-upgrade-preflight-disk-check:
   summary: Verify pre-flight disk space check rejects images with inflated layer sizes
-  duration: 20m
+  duration: 10m
   test: nu booted/test-upgrade-preflight-disk-check.nu
 
 /test-36-rollback:
-  summary: Test bootc rollback functionality through image switch and rollback cycle
+  summary: Test bootc rollback functionality
   duration: 30m
   test: nu booted/test-rollback.nu
 
@@ -121,3 +121,8 @@
   summary: Test bootc install with --bootloader=none
   duration: 30m
   test: nu booted/test-install-bootloader-none.nu
+
+/test-39-composefs-upgrade:
+  summary: Test composefs upgrade with pre-built (optionally sealed) image
+  duration: 30m
+  test: nu booted/test-composefs-upgrade.nu