diff --git a/tests/ci_build/Dockerfile.cpu b/tests/ci_build/Dockerfile.cpu
index 0aa29a111..1890a64ea 100644
--- a/tests/ci_build/Dockerfile.cpu
+++ b/tests/ci_build/Dockerfile.cpu
@@ -24,7 +24,7 @@ RUN \
     pip install pyyaml cpplint pylint astroid sphinx numpy scipy pandas matplotlib sh recommonmark guzzle_sphinx_theme mock \
                 breathe matplotlib graphviz pytest scikit-learn wheel kubernetes urllib3 && \
     pip install https://h2o-release.s3.amazonaws.com/datatable/stable/datatable-0.7.0/datatable-0.7.0-cp37-cp37m-linux_x86_64.whl && \
-    pip install "dask[complete]==2.0.0"
+    pip install "dask[complete]"
 
 # Install lightweight sudo (not bound to TTY)
 RUN set -ex; \
diff --git a/tests/ci_build/Dockerfile.cudf b/tests/ci_build/Dockerfile.cudf
index 4523e6ac5..02d6c9325 100644
--- a/tests/ci_build/Dockerfile.cudf
+++ b/tests/ci_build/Dockerfile.cudf
@@ -18,7 +18,7 @@ ENV PATH=/opt/python/bin:$PATH
 # Create new Conda environment with cuDF and dask
 RUN \
     conda create -n cudf_test -c rapidsai -c nvidia -c numba -c conda-forge -c anaconda \
-        cudf=0.9 python=3.7 anaconda::cudatoolkit=$CUDA_VERSION dask=2.0.0
+        cudf=0.9 python=3.7 anaconda::cudatoolkit=$CUDA_VERSION dask
 
 # Install other Python packages
 RUN \
diff --git a/tests/ci_build/Dockerfile.gpu b/tests/ci_build/Dockerfile.gpu
index 183d8c363..533110019 100644
--- a/tests/ci_build/Dockerfile.gpu
+++ b/tests/ci_build/Dockerfile.gpu
@@ -17,7 +17,7 @@ ENV PATH=/opt/python/bin:$PATH
 # Install Python packages
 RUN \
     pip install numpy pytest scipy scikit-learn pandas matplotlib wheel kubernetes urllib3 graphviz && \
-    pip install "dask[complete]==2.0.0"
+    pip install "dask[complete]"
 
 ENV GOSU_VERSION 1.10