diff --git a/google/cloud/sql/connector/version.py b/google/cloud/sql/connector/version.py
index 00f025e20..8458f9ef3 100644
--- a/google/cloud/sql/connector/version.py
+++ b/google/cloud/sql/connector/version.py
@@ -12,4 +12,4 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-__version__ = "0.4.0"
+__version__ = "0.4.0-dev"