diff --git a/ci/test_python_dask.sh b/ci/test_python_dask.sh
index 34a319f25a..c6b5efe739 100755
--- a/ci/test_python_dask.sh
+++ b/ci/test_python_dask.sh
@@ -11,6 +11,10 @@ EXITCODE=0
 trap "EXITCODE=1" ERR
 set +e
 
+# TODO: Enable dask query planning (by default) once some bugs are fixed.
+# xref: https://github.com/rapidsai/cudf/issues/15027
+export DASK_DATAFRAME__QUERY_PLANNING=False
+
 rapids-logger "pytest cuml-dask"
 ./ci/run_cuml_dask_pytests.sh \
   --junitxml="${RAPIDS_TESTS_DIR}/junit-cuml-dask.xml" \
diff --git a/ci/test_wheel.sh b/ci/test_wheel.sh
index 0ecbd6a430..95efa9a5cf 100755
--- a/ci/test_wheel.sh
+++ b/ci/test_wheel.sh
@@ -1,5 +1,5 @@
 #!/bin/bash
-# Copyright (c) 2023, NVIDIA CORPORATION.
+# Copyright (c) 2023-2024, NVIDIA CORPORATION.
 
 set -euo pipefail
 
@@ -19,6 +19,10 @@ EXITCODE=0
 trap "EXITCODE=1" ERR
 set +e
 
+# TODO: Enable dask query planning (by default) once some bugs are fixed.
+# xref: https://github.com/rapidsai/cudf/issues/15027
+export DASK_DATAFRAME__QUERY_PLANNING=False
+
 # Run smoke tests for aarch64 pull requests
 if [[ "$(arch)" == "aarch64" && "${RAPIDS_BUILD_TYPE}" == "pull-request" ]]; then
     python ci/wheel_smoke_test_cuml.py