diff --git a/repo2docker/buildpacks/conda/install-base-env.bash b/repo2docker/buildpacks/conda/install-base-env.bash
index 9e3b9ffa..69ff4397 100755
--- a/repo2docker/buildpacks/conda/install-base-env.bash
+++ b/repo2docker/buildpacks/conda/install-base-env.bash
@@ -5,7 +5,7 @@ set -ex
 
 cd $(dirname $0)
 
-export MAMBA_VERSION="2.0.0rc3"
+export MAMBA_VERSION="2.0.0rc4"
 export CONDA_VERSION=24.7.0
 
 URL="https://anaconda.org/conda-forge/micromamba/${MAMBA_VERSION}/download/${CONDA_PLATFORM}/micromamba-${MAMBA_VERSION}-0.tar.bz2"