diff --git a/requirements-testing.txt b/requirements-testing.txt
index 516c992f..b21c5f69 100644
--- a/requirements-testing.txt
+++ b/requirements-testing.txt
@@ -6,4 +6,4 @@ pytest-xdist == 3.7.*
 types-PyYAML ~= 6.0
 black == 25.*
 ruff == 0.11.*
-mypy == 1.15.*
+mypy == 1.16.*
diff --git a/src/openjd/model/_merge_job_parameter.py b/src/openjd/model/_merge_job_parameter.py
index fe3dae8e..34f6699f 100644
--- a/src/openjd/model/_merge_job_parameter.py
+++ b/src/openjd/model/_merge_job_parameter.py
@@ -197,10 +197,7 @@ def merge_job_parameter_definitions_for_one(
     if errors:
         raise CompatibilityError("\n".join(errors))
 
-    return cast(
-        JobParameterDefinition,
-        parse_model(model=params[0].definition.__class__, obj=merged_properties),
-    )
+    return parse_model(model=params[0].definition.__class__, obj=merged_properties)
 
 
 def _merge_allowed_values(
diff --git a/src/openjd/model/v2023_09/_model.py b/src/openjd/model/v2023_09/_model.py
index 9189bbb1..f0aa1446 100644
--- a/src/openjd/model/v2023_09/_model.py
+++ b/src/openjd/model/v2023_09/_model.py
@@ -2675,7 +2675,7 @@ def _validate_env_names_dont_match_step_env_names(self) -> Self:
         if not envlist:
             return self
 
-        job_env_names = set(env.name for env in cast(JobEnvironmentsList, envlist))
+        job_env_names = set(env.name for env in envlist)
 
         errors = list[InitErrorDetails]()
         for i, step in enumerate(steplist):