diff --git a/repo2docker/buildpacks/conda/install-base-env.bash b/repo2docker/buildpacks/conda/install-base-env.bash
index 65d07a62..7d327052 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="2.1.0"
-export CONDA_VERSION=24.11.0
+export MAMBA_VERSION="2.3.2"
+export CONDA_VERSION="25.7.0"
 
 URL="https://anaconda.org/conda-forge/micromamba/${MAMBA_VERSION}/download/${CONDA_PLATFORM}/micromamba-${MAMBA_VERSION}-0.tar.bz2"
 
diff --git a/tests/conda/downgrade/verify b/tests/conda/downgrade/verify
index 2c69b3e8..4eead7df 100755
--- a/tests/conda/downgrade/verify
+++ b/tests/conda/downgrade/verify
@@ -24,7 +24,7 @@ assert pkgs["xeus-cling"]["version"] == "0.6.0"
 # this may be brittle, but it's unlikely any of these old versions
 # of packages will be rebuilt
 # xeus-cling 0.6.0 pins xeus 0.20, which pins openssl 1.1.1,
-# which in turn downgrades Python from >=3.9.16 to 3.9.6
+# which in turn downgrades krb5 from >=1.21.3 to 1.17.2
 
 assert pkgs["openssl"]["version"].startswith("1.1.1"), pkgs["openssl"]["version"]
-assert pkgs["python"]["version"] == "3.9.0", pkgs["python"]["version"]
+assert pkgs["krb5"]["version"] == "1.17.2", pkgs["krb5"]["version"]
diff --git a/tests/conda/py35-binder-dir/verify b/tests/conda/py35-binder-dir/verify
index 11a1b3d7..31538438 100755
--- a/tests/conda/py35-binder-dir/verify
+++ b/tests/conda/py35-binder-dir/verify
@@ -16,10 +16,10 @@ v = out.split()[1]
 assert v[:3] == "3.5", out
 
 out = sh(["micromamba", "--version"])
-assert out == "2.1.0", out
+assert out == "2.3.2", out
 
 out = sh(["mamba", "--version"])
-assert out == "2.1.0", out
+assert out == "2.3.2", out
 
 
 sh([kernel_python, "-c", "import numpy"])