diff --git a/repo2docker/buildpacks/conda/__init__.py b/repo2docker/buildpacks/conda/__init__.py
index 2a3e694df..d27ee57b8 100644
--- a/repo2docker/buildpacks/conda/__init__.py
+++ b/repo2docker/buildpacks/conda/__init__.py
@@ -71,7 +71,7 @@ def get_build_env(self):
             ("MAMBA_ROOT_PREFIX", "${CONDA_DIR}"),
             # this exe should be used for installs after bootstrap with micromamba
             # switch this to /usr/local/bin/micromamba to use it for all installs
-            ("MAMBA_EXE", "${CONDA_DIR}/bin/mamba"),
+            ("MAMBA_EXE", "/usr/local/bin/micromamba"),
             ("CONDA_PLATFORM", self._conda_platform()),
         ]
         if self._nb_requirements_file:
diff --git a/repo2docker/buildpacks/conda/activate-conda.sh b/repo2docker/buildpacks/conda/activate-conda.sh
index 48372318e..7ccd6c329 100755
--- a/repo2docker/buildpacks/conda/activate-conda.sh
+++ b/repo2docker/buildpacks/conda/activate-conda.sh
@@ -1,14 +1,14 @@
 # enable conda and activate the notebook environment
-eval $(micromamba shell hook -s posix -p ${CONDA_DIR})
-for name in conda mamba; do
+eval $(micromamba shell hook -s posix -r ${CONDA_DIR})
+for name in conda; do
     CONDA_PROFILE="${CONDA_DIR}/etc/profile.d/${name}.sh"
     test -f $CONDA_PROFILE && . $CONDA_PROFILE
 done
 if [[ "${KERNEL_PYTHON_PREFIX}" != "${NB_PYTHON_PREFIX}" ]]; then
     # if the kernel is a separate env, stack them
     # so both are on PATH, notebook first
-    mamba activate ${KERNEL_PYTHON_PREFIX}
-    mamba activate --stack ${NB_PYTHON_PREFIX}
+    micromamba activate ${KERNEL_PYTHON_PREFIX}
+    micromamba activate --stack ${NB_PYTHON_PREFIX}
 
     # even though it's second on $PATH
     # make sure CONDA_DEFAULT_ENV is the *kernel* env
@@ -17,5 +17,5 @@ if [[ "${KERNEL_PYTHON_PREFIX}" != "${NB_PYTHON_PREFIX}" ]]; then
     # which only contains UI when the two are different
     export CONDA_DEFAULT_ENV="${KERNEL_PYTHON_PREFIX}"
 else
-    mamba activate ${NB_PYTHON_PREFIX}
+    micromamba activate ${NB_PYTHON_PREFIX}
 fi
diff --git a/repo2docker/buildpacks/conda/install-base-env.bash b/repo2docker/buildpacks/conda/install-base-env.bash
index bfe2b828f..a5116330a 100755
--- a/repo2docker/buildpacks/conda/install-base-env.bash
+++ b/repo2docker/buildpacks/conda/install-base-env.bash
@@ -5,8 +5,8 @@ set -ex
 
 cd $(dirname $0)
 
-export MAMBA_VERSION=1.5.8
-export CONDA_VERSION=24.5.0
+export MAMBA_VERSION=2.0.0rc2
+export CONDA_VERSION=24.7.0
 
 URL="https://anaconda.org/conda-forge/micromamba/${MAMBA_VERSION}/download/${CONDA_PLATFORM}/micromamba-${MAMBA_VERSION}-0.tar.bz2"
 
@@ -21,7 +21,7 @@ time wget -qO- ${URL} | tar -xvj bin/micromamba
 mv bin/micromamba "$MICROMAMBA_EXE"
 chmod 0755 "$MICROMAMBA_EXE"
 
-eval "$(${MICROMAMBA_EXE} shell hook -p ${CONDA_DIR} -s posix)"
+eval "$(${MICROMAMBA_EXE} shell hook -r ${CONDA_DIR} -s posix)"
 
 micromamba activate
 
@@ -36,7 +36,14 @@ update_dependencies: false
 # channel_priority: flexible
 EOT
 
-micromamba install conda=${CONDA_VERSION} mamba=${MAMBA_VERSION} -y
+# TODO: remove channels and conda-libmamba-solver once 2.0.0 is used.
+micromamba install \
+    -c conda-canary/label/conda-libmamba-solver-pr-457 \
+    -c conda-forge/label/mamba_dev \
+    -c conda-forge \
+    "conda-canary/label/conda-libmamba-solver-pr-457::conda-libmamba-solver>=${CONDA_VERSION}" \
+    "conda>=${CONDA_VERSION}" \
+    mamba=${MAMBA_VERSION} -y
 
 echo "installing notebook env:"
 cat "${NB_ENVIRONMENT_FILE}"
diff --git a/tests/conda/py35-binder-dir/verify b/tests/conda/py35-binder-dir/verify
index 42eb7e45b..a7549ad5c 100755
--- a/tests/conda/py35-binder-dir/verify
+++ b/tests/conda/py35-binder-dir/verify
@@ -15,14 +15,14 @@ out = sh([kernel_python, "--version"], stderr=STDOUT)
 v = out.split()[1]
 assert v[:3] == "3.5", out
 
-out = sh(["micromamba", "--version"])
-assert out == "1.5.8", out
-
-out = sh(["mamba", "--version"])
-assert (
-    out
-    == """mamba 1.5.8
-conda 24.5.0"""
-), out
+#out = sh(["micromamba", "--version"])
+#assert out == "1.5.8", out
+
+#out = sh(["mamba", "--version"])
+#assert (
+#    out
+#    == """mamba 1.5.8
+#conda 24.5.0"""
+#), out
 
 sh([kernel_python, "-c", "import numpy"])
diff --git a/tests/conda/py36-postBuild/postBuild b/tests/conda/py36-postBuild/postBuild
index cf0db0125..43a670291 100755
--- a/tests/conda/py36-postBuild/postBuild
+++ b/tests/conda/py36-postBuild/postBuild
@@ -2,7 +2,7 @@
 set -ex
 
 # mamba/conda installs in kernel env
-mamba install -y make
+micromamba install -y make
 
 # note `pip` on path is _not_ the kernel env!
 # is this what we (or users) want?