diff --git a/spkrepo/models.py b/spkrepo/models.py
index 6394480..c94dc53 100644
--- a/spkrepo/models.py
+++ b/spkrepo/models.py
@@ -1,4 +1,5 @@
 # -*- coding: utf-8 -*-
+import hashlib
 import io
 import os
 import shutil
@@ -360,6 +361,24 @@ def save(self, stream):
         ) as f:
             f.write(stream.read())
 
+    def calculate_md5(self):
+        if not self.path:
+            raise ValueError("Path cannot be empty.")
+
+        file_path = os.path.join(current_app.config["DATA_PATH"], self.path)
+
+        if not os.path.exists(file_path):
+            raise FileNotFoundError(f"File not found at path: {file_path}")
+
+        if self.md5 is None:
+            with io.open(file_path, "rb") as f:
+                md5_hash = hashlib.md5()
+                for chunk in iter(lambda: f.read(4096), b""):
+                    md5_hash.update(chunk)
+                return md5_hash.hexdigest()
+
+        return self.md5
+
     def _after_insert(self):
         assert os.path.exists(os.path.join(current_app.config["DATA_PATH"], self.path))
 
diff --git a/spkrepo/tests/common.py b/spkrepo/tests/common.py
index cb43261..1682b9b 100644
--- a/spkrepo/tests/common.py
+++ b/spkrepo/tests/common.py
@@ -281,8 +281,7 @@ def create_spk(self, create, extracted, **kwargs):
         with create_spk(self) as spk_stream:
             self.save(spk_stream)
             if self.md5 is None:
-                spk_stream.seek(0)
-                self.md5 = hashlib.md5(spk_stream.read()).hexdigest()
+                self.md5 = self.calculate_md5()
         spk_stream.close()
 
     @classmethod
diff --git a/spkrepo/utils.py b/spkrepo/utils.py
index c5d4043..aa0b0ab 100644
--- a/spkrepo/utils.py
+++ b/spkrepo/utils.py
@@ -345,6 +345,18 @@ def unsign(self):
         self.stream.truncate()
         self.stream.seek(0)
 
+    def calculate_md5(self):
+        md5_hash = hashlib.md5()
+
+        # Ensure the stream position is at the beginning
+        self.stream.seek(0)
+
+        # Update MD5 hash directly from the stream
+        for chunk in iter(lambda: self.stream.read(4096), b""):
+            md5_hash.update(chunk)
+
+        return md5_hash.hexdigest()
+
     def _generate_signature(self, stream, timestamp_url, gnupghome):  # pragma: no cover
         # generate the signature
         gpg = gnupg.GPG(gnupghome=gnupghome)
diff --git a/spkrepo/views/admin.py b/spkrepo/views/admin.py
index 943ecff..0b096de 100644
--- a/spkrepo/views/admin.py
+++ b/spkrepo/views/admin.py
@@ -428,8 +428,11 @@ def action_sign(self, ids):
                                 current_app.config["GNUPG_TIMESTAMP_URL"],
                                 current_app.config["GNUPG_PATH"],
                             )
+                            build.md5 = spk.calculate_md5()
+                            self.session.commit()
                             success.append(filename)
                         except Exception:
+                            self.session.rollback()
                             failed.append(filename)
                 if failed:
                     if len(failed) == 1:
@@ -479,8 +482,11 @@ def action_unsign(self, ids):
                             continue
                         try:
                             spk.unsign()
+                            build.md5 = spk.calculate_md5()
+                            self.session.commit()
                             success.append(filename)
                         except Exception:
+                            self.session.rollback()
                             failed.append(filename)
                 if failed:
                     if len(failed) == 1:
@@ -683,8 +689,11 @@ def action_sign(self, ids):
                             current_app.config["GNUPG_TIMESTAMP_URL"],
                             current_app.config["GNUPG_PATH"],
                         )
+                        build.md5 = spk.calculate_md5()
+                        self.session.commit()
                         success.append(filename)
                     except Exception:
+                        self.session.rollback()
                         failed.append(filename)
             if failed:
                 if len(failed) == 1:
@@ -733,8 +742,11 @@ def action_unsign(self, ids):
                         continue
                     try:
                         spk.unsign()
+                        build.md5 = spk.calculate_md5()
+                        self.session.commit()
                         success.append(filename)
                     except Exception:
+                        self.session.rollback()
                         failed.append(filename)
             if failed:
                 if len(failed) == 1:
diff --git a/spkrepo/views/api.py b/spkrepo/views/api.py
index 9580bfd..593a73f 100644
--- a/spkrepo/views/api.py
+++ b/spkrepo/views/api.py
@@ -278,6 +278,8 @@ def post(self):
                 for size, icon in build.version.icons.items():
                     icon.save(spk.icons[size])
             build.save(spk.stream)
+            # generate md5 hash
+            build.md5 = build.calculate_md5()
         except Exception as e:  # pragma: no cover
             if create_package:
                 shutil.rmtree(os.path.join(data_path, package.name), ignore_errors=True)