diff --git a/CITATION.cff b/CITATION.cff
index f6836cf..262e520 100644
--- a/CITATION.cff
+++ b/CITATION.cff
@@ -33,5 +33,5 @@ keywords:
   - spectroscopy
   - submillimeter
 license: MIT
-version: 2025.8.3
-date-released: '2025-08-15'
+version: 2025.8.4
+date-released: '2025-08-21'
diff --git a/README.md b/README.md
index 5f5158b..c2cce0f 100644
--- a/README.md
+++ b/README.md
@@ -11,7 +11,7 @@ DESHIMA merge code for observed datasets
 ## Installation
 
 ```shell
-pip install demerge==2025.8.3
+pip install demerge==2025.8.4
 ```
 
 ## Command line interface
@@ -56,7 +56,7 @@ FLAGS
         Path of CDB (KID correspondence database) file.
     --ddb=DDB
         Type: Path
-        Default: PosixPath('/path/to/demerge/data/ddb_20250814.fits.gz')
+        Default: PosixPath('/path/to/demerge/data/ddb_20250819.fits.gz')
         Path of DDB (DESHIMA database) file.
     --overwrite=OVERWRITE
         Type: bool
diff --git a/demerge/__init__.py b/demerge/__init__.py
index 8b60b82..4f7247a 100644
--- a/demerge/__init__.py
+++ b/demerge/__init__.py
@@ -1,5 +1,5 @@
 __all__ = ["data", "demerge", "merge", "reduce"]
-__version__ = "2025.8.3"
+__version__ = "2025.8.4"
 
 
 # standard library
@@ -59,7 +59,7 @@ def demerge(
     dems_dir: StrPath = Path(),
     reduced_dir: Optional[Path] = None,
     cdb: StrPath = PACKAGE_DATA / "cdb_20250528.zarr.zip",
-    ddb: StrPath = PACKAGE_DATA / "ddb_20250814.fits.gz",
+    ddb: StrPath = PACKAGE_DATA / "ddb_20250819.fits.gz",
     # merge options
     overwrite: bool = False,
     debug: bool = False,
diff --git a/demerge/data/ddb_20250814.fits.gz b/demerge/data/ddb_20250819.fits.gz
similarity index 79%
rename from demerge/data/ddb_20250814.fits.gz
rename to demerge/data/ddb_20250819.fits.gz
index 0323d4e..7b83ba8 100644
Binary files a/demerge/data/ddb_20250814.fits.gz and b/demerge/data/ddb_20250819.fits.gz differ
diff --git a/pyproject.toml b/pyproject.toml
index e2a13a7..19b788a 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -1,6 +1,6 @@
 [project]
 name = "demerge"
-version = "2025.8.3"
+version = "2025.8.4"
 description = "DESHIMA merge code for observed datasets"
 readme = "README.md"
 keywords = [
diff --git a/uv.lock b/uv.lock
index 99bbdef..0650c0b 100644
--- a/uv.lock
+++ b/uv.lock
@@ -498,7 +498,7 @@ wheels = [
 
 [[package]]
 name = "demerge"
-version = "2025.8.3"
+version = "2025.8.4"
 source = { editable = "." }
 dependencies = [
     { name = "astropy", version = "6.0.1", source = { registry = "https://pypi.org/simple" }, marker = "python_full_version < '3.10'" },