diff --git a/addons/account_asset/account_asset.py b/addons/account_asset/account_asset.py
index 951c28a8a7a..dd68362da39 100644
--- a/addons/account_asset/account_asset.py
+++ b/addons/account_asset/account_asset.py
@@ -165,8 +165,12 @@ class AccountAssetAsset(models.Model):
             if self.prorata:
                 depreciation_date = datetime.strptime(self._get_last_depreciation_date()[self.id], DF).date()
             else:
-                # depreciation_date = 1st of January of purchase year
-                asset_date = datetime.strptime(self.date[:4] + '-01-01', DF).date()
+                # depreciation_date = 1st of January of purchase year if annual valuation, 1st of
+                # purchase month in other cases
+                if self.method_period >= 12:
+                    asset_date = datetime.strptime(self.date[:4] + '-01-01', DF).date()
+                else:
+                    asset_date = datetime.strptime(self.date[:7] + '-01', DF).date()
                 # if we already have some previous validated entries, starting date isn't 1st January but last entry + method period
                 if posted_depreciation_line_ids and posted_depreciation_line_ids[-1].depreciation_date:
                     last_depreciation_date = datetime.strptime(posted_depreciation_line_ids[-1].depreciation_date, DF).date()