diff --git a/.github/unittest/install_smacv2.sh b/.github/unittest/install_smacv2.sh
index fd57cf0a..7feab7ef 100644
--- a/.github/unittest/install_smacv2.sh
+++ b/.github/unittest/install_smacv2.sh
@@ -18,5 +18,4 @@ mkdir "${map_dir}/SMAC_Maps"
 mv *.SC2Map "${map_dir}/SMAC_Maps"
 printf "StarCraft II and SMAC are installed."
 
-pip install numpy==1.23.0
 pip install git+https://github.com/oxwhirl/smacv2.git
diff --git a/benchmarl/algorithms/isac.py b/benchmarl/algorithms/isac.py
index 972b762f..f219a13c 100644
--- a/benchmarl/algorithms/isac.py
+++ b/benchmarl/algorithms/isac.py
@@ -234,6 +234,7 @@ def _get_policy_for_loss(
                         "logits": (group, "logits"),
                         "mask": (group, "action_mask"),
                     },
+                    distribution_kwargs={"neg_inf": -18.0},
                     out_keys=[(group, "action")],
                     distribution_class=MaskedCategorical,
                     return_log_prob=True,
diff --git a/benchmarl/algorithms/masac.py b/benchmarl/algorithms/masac.py
index 291a6588..9323aadf 100644
--- a/benchmarl/algorithms/masac.py
+++ b/benchmarl/algorithms/masac.py
@@ -229,6 +229,7 @@ def _get_policy_for_loss(
                         "mask": (group, "action_mask"),
                     },
                     out_keys=[(group, "action")],
+                    distribution_kwargs={"neg_inf": -18.0},
                     distribution_class=MaskedCategorical,
                     return_log_prob=True,
                     log_prob_key=(group, "log_prob"),