diff --git a/bob/devtools/bootstrap.py b/bob/devtools/bootstrap.py
index 6bca51c07ee302640e52fecf6201c88968d04fed..a6d9af536635e4921f7d298f6ddc594dcf26fbc8 100644
--- a/bob/devtools/bootstrap.py
+++ b/bob/devtools/bootstrap.py
@@ -506,7 +506,7 @@ if __name__ == "__main__":
 
     conda_version = "4"
     conda_build_version = "3"
-    mamba_version = "0.16"
+    mamba_version = "0.15"
     boa_version = "0.6"
 
     conda_verbosity = []
diff --git a/conda/meta.yaml b/conda/meta.yaml
index 9337f23c80a3470904e90f76ce051186b2b1340a..fbfa05c8d674af9b796014f529679b1d97c91728 100644
--- a/conda/meta.yaml
+++ b/conda/meta.yaml
@@ -33,7 +33,7 @@ requirements:
     - click-plugins
     - conda=4
     - conda-build=3
-    - mamba=0.16
+    - mamba=0.15
     - boa=0.6
     - certifi
     - docformatter