diff --git a/imblearn/_version.py b/imblearn/_version.py
index c97eb6b29..b25b802af 100644
--- a/imblearn/_version.py
+++ b/imblearn/_version.py
@@ -22,4 +22,4 @@
 # 'X.Y.dev0' is the canonical version of 'X.Y.dev'
 #
 
-__version__ = "0.9.0.dev0"
+__version__ = "0.9.0"
diff --git a/setup.cfg b/setup.cfg
index b9eae29e4..3f38ce854 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -1,14 +1,14 @@
 [bumpversion]
-current_version = 0.9.0.dev0
+current_version = 0.9.0
 tag = False
 parse = (?P<major>\d+)\.(?P<minor>\d+)\.(?P<patch>\d+)(\.(?P<release>[a-z]+)(?P<dev>\d+))?
-serialize =
+serialize = 
 	{major}.{minor}.{patch}.{release}{dev}
 	{major}.{minor}.{patch}
 
 [bumpversion:part:release]
 optional_value = gamma
-values =
+values = 
 	dev
 	gamma
 
@@ -22,19 +22,20 @@ test = pytest
 [tool:pytest]
 doctest_optionflags = NORMALIZE_WHITESPACE ELLIPSIS
 testpaths = imblearn
-addopts =
+addopts = 
 	--doctest-modules
 	--color=yes
 	-rs
-filterwarnings =
+filterwarnings = 
 	ignore:the matrix subclass:PendingDeprecationWarning
 
 [flake8]
 max-line-length = 88
 ignore = E121,E123,E126,E226,E24,E704,W503,W504,E203
-per-file-ignores =
+per-file-ignores = 
 	examples/*: E402
 
 [mypy]
 ignore_missing_imports = True
 allow_redefinition = True
+