diff --git a/.github/workflows/build_all.yml b/.github/workflows/build_all.yml
index 1ee1cbd012..c39501680c 100644
--- a/.github/workflows/build_all.yml
+++ b/.github/workflows/build_all.yml
@@ -170,7 +170,7 @@ jobs:
           git_commit_hash="${{ github.event.pull_request.head.sha }}"
         else
           ver=V$ver_pure
-          git_commit_hash=""
+          git_commit_hash="${{ github.sha }}"
         fi
         echo "ver=$ver" >> $GITHUB_ENV
         echo "ver_pure=$ver_pure" >> $GITHUB_ENV
@@ -197,6 +197,11 @@ jobs:
         sed -i '0,/^finish-args:/s//build-options:\n  no-debuginfo: true\n  strip: true\nfinish-args:/' \
           scripts/flatpak/io.github.orcaslicer.OrcaSlicer.yml
       shell: bash
+    - name: Inject git commit hash into Flatpak manifest
+      run: |
+        sed -i "/name: OrcaSlicer/{n;s|buildsystem: simple|buildsystem: simple\n    build-options:\n      env:\n        git_commit_hash: \"$git_commit_hash\"|}" \
+          scripts/flatpak/io.github.orcaslicer.OrcaSlicer.yml
+      shell: bash
     - uses: flatpak/flatpak-github-actions/flatpak-builder@master
       with:
         bundle: OrcaSlicer-Linux-flatpak_${{ env.ver }}_${{ matrix.variant.arch }}.flatpak
diff --git a/CMakeLists.txt b/CMakeLists.txt
index 9356c308ee..8f47f3a944 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -89,10 +89,9 @@ else ()
 endif ()
 
 find_package(Git)
-if(GIT_FOUND AND EXISTS "${CMAKE_SOURCE_DIR}/.git")
-    if(DEFINED ENV{git_commit_hash} AND NOT "$ENV{git_commit_hash}" STREQUAL "")
-        message(STATUS "Specified git commit hash: $ENV{git_commit_hash}")
-
+if(DEFINED ENV{git_commit_hash} AND NOT "$ENV{git_commit_hash}" STREQUAL "")
+    message(STATUS "Specified git commit hash: $ENV{git_commit_hash}")
+    if(GIT_FOUND AND EXISTS "${CMAKE_SOURCE_DIR}/.git")
         # Convert the given hash to short hash
         execute_process(
             COMMAND ${GIT_EXECUTABLE} rev-parse --short "$ENV{git_commit_hash}"
@@ -100,17 +99,20 @@ if(GIT_FOUND AND EXISTS "${CMAKE_SOURCE_DIR}/.git")
             OUTPUT_VARIABLE GIT_COMMIT_HASH
             OUTPUT_STRIP_TRAILING_WHITESPACE
         )
-        add_definitions("-DGIT_COMMIT_HASH=\"${GIT_COMMIT_HASH}\"")
     else()
-        # Check current Git commit hash
-        execute_process(
-            COMMAND ${GIT_EXECUTABLE} log -1 --format=%h
-            WORKING_DIRECTORY ${CMAKE_SOURCE_DIR}
-            OUTPUT_VARIABLE GIT_COMMIT_HASH
-            OUTPUT_STRIP_TRAILING_WHITESPACE
-        )
-        add_definitions("-DGIT_COMMIT_HASH=\"${GIT_COMMIT_HASH}\"")
+        # No .git directory (e.g., Flatpak sandbox) — truncate directly
+        string(SUBSTRING "$ENV{git_commit_hash}" 0 7 GIT_COMMIT_HASH)
     endif()
+    add_definitions("-DGIT_COMMIT_HASH=\"${GIT_COMMIT_HASH}\"")
+elseif(GIT_FOUND AND EXISTS "${CMAKE_SOURCE_DIR}/.git")
+    # Check current Git commit hash
+    execute_process(
+        COMMAND ${GIT_EXECUTABLE} log -1 --format=%h
+        WORKING_DIRECTORY ${CMAKE_SOURCE_DIR}
+        OUTPUT_VARIABLE GIT_COMMIT_HASH
+        OUTPUT_STRIP_TRAILING_WHITESPACE
+    )
+    add_definitions("-DGIT_COMMIT_HASH=\"${GIT_COMMIT_HASH}\"")
 endif()
 
 if(DEFINED ENV{SLIC3R_STATIC})