diff --git a/environment.yml b/environment.yml
index c45d8102a..a08341b2d 100644
--- a/environment.yml
+++ b/environment.yml
@@ -11,6 +11,7 @@ dependencies:
   - konnektor~=0.2.0
   - lomap2>=3.2.1
   - networkx
+  - numba
   - numpy
   - openfe-analysis>=0.3.1
   - openff-interchange-base
@@ -54,6 +55,7 @@ dependencies:
   - threadpoolctl
   - pip:
     - git+https://github.com/OpenFreeEnergy/gufe@main
+    - git+https://github.com/choderalab/pymbar.git@ed40ec3bbef03bb08938ad1a74d459b0d1ab81f7
   - run_constrained:
     # drop this pin when handled upstream in espaloma-feedstock
     - smirnoff99frosst>=1.1.0.1  #https://github.com/openforcefield/smirnoff99Frosst/issues/109
diff --git a/src/openfe/protocols/openmm_utils/multistate_analysis.py b/src/openfe/protocols/openmm_utils/multistate_analysis.py
index 6f1d785d2..19803a283 100644
--- a/src/openfe/protocols/openmm_utils/multistate_analysis.py
+++ b/src/openfe/protocols/openmm_utils/multistate_analysis.py
@@ -241,7 +241,7 @@ def _get_free_energy(
         mbar = MBAR(
             u_ln,
             N_l,
-            solver_protocol="robust",
+            solver_protocol="numba",
             n_bootstraps=bootstraps,
             bootstrap_solver_protocol="robust",
         )