diff --git a/src/dirac_cwl/submission_models.py b/src/dirac_cwl/submission_models.py
index 3033629..53fc620 100644
--- a/src/dirac_cwl/submission_models.py
+++ b/src/dirac_cwl/submission_models.py
@@ -13,6 +13,7 @@
 from cwl_utils.parser.cwl_v1_2 import (
     CommandLineTool,
     ExpressionTool,
+    ResourceRequirement,
     Workflow,
 )
 from pydantic import BaseModel, ConfigDict, field_serializer, model_validator
@@ -55,6 +56,23 @@ class BaseJobModel(BaseModel):
 
     task: CommandLineTool | Workflow | ExpressionTool
 
+    @model_validator(mode="before")
+    def validate_job(cls, values):
+        """Validate job workflow.
+
+        :param values: Model values dictionary.
+        :return: Validated values dictionary.
+        """
+        task = values.get("task")
+
+        # ResourceRequirement validation
+        validate_resource_requirements(task)
+
+        # Hints validation
+        ExecutionHooksHint.from_cwl(task), SchedulingHint.from_cwl(task)
+
+        return values
+
     @field_serializer("task")
     def serialize_task(self, value):
         """Serialize CWL task object to dictionary.
@@ -68,17 +86,6 @@ def serialize_task(self, value):
         else:
             raise TypeError(f"Cannot serialize type {type(value)}")
 
-    @model_validator(mode="before")
-    def validate_hints(cls, values):
-        """Validate execution hooks and scheduling hints in the task.
-
-        :param values: Model values dictionary.
-        :return: Validated values dictionary.
-        """
-        task = values.get("task")
-        ExecutionHooksHint.from_cwl(task), SchedulingHint.from_cwl(task)
-        return values
-
 
 class JobSubmissionModel(BaseJobModel):
     """Job definition sent to the router."""
@@ -119,14 +126,20 @@ def serialize_task(self, value):
             raise TypeError(f"Cannot serialize type {type(value)}")
 
     @model_validator(mode="before")
-    def validate_hints(cls, values):
-        """Validate transformation execution hooks and scheduling hints in the task.
+    def validate_transformation(cls, values):
+        """Validate transformation workflow.
 
         :param values: Model values dictionary.
         :return: Validated values dictionary.
         """
         task = values.get("task")
+
+        # ResourceRequirement validation
+        validate_resource_requirements(task)
+
+        # Hints validation
         TransformationExecutionHooksHint.from_cwl(task), SchedulingHint.from_cwl(task)
+
         return values
 
 
@@ -155,3 +168,56 @@ def serialize_task(self, value):
             return save(value)
         else:
             raise TypeError(f"Cannot serialize type {type(value)}")
+
+    @model_validator(mode="before")
+    def validate_production(cls, values):
+        """Validate production workflow."""
+        task = values.get("task")
+
+        # ResourceRequirement validation
+        validate_resource_requirements(task)
+
+        return values
+
+
+# -----------------------------------------------------------------------------
+# ResourceRequirement validations
+# -----------------------------------------------------------------------------
+# Temporary code, waiting on cwltool PR: https://github.com/common-workflow-language/cwltool/pull/2179.
+
+
+def validate_resource_requirements(task: CommandLineTool | Workflow | ExpressionTool):
+    """Validate ResourceRequirements of a task recursively.
+
+    :param task: The task to validate.
+    :raises ValueError: If any ResourceRequirement has min > max.
+    """
+    # Validate task-level requirements
+    for req in getattr(task, "requirements", None) or []:
+        if isinstance(req, ResourceRequirement):
+            _validate_min_max(req)
+
+    # Recurse into workflow steps
+    if isinstance(task, Workflow):
+        for step in task.steps or []:
+            for req in getattr(step, "requirements", None) or []:
+                if isinstance(req, ResourceRequirement):
+                    _validate_min_max(req)
+            if step.run:
+                validate_resource_requirements(step.run)
+
+
+def _validate_min_max(req: ResourceRequirement):
+    """Check that min does not exceed max for any resource.
+
+    :param req: The ResourceRequirement to validate.
+    :raises ValueError: If min > max for any resource.
+    """
+    for name, lo, hi in [
+        ("cores", req.coresMin, req.coresMax),
+        ("ram", req.ramMin, req.ramMax),
+        ("tmpdir", req.tmpdirMin, req.tmpdirMax),
+        ("outdir", req.outdirMin, req.outdirMax),
+    ]:
+        if lo and hi and lo > hi:
+            raise ValueError(f"{name}Min ({lo}) exceeds {name}Max ({hi})")
diff --git a/test/test_resource_requirements.py b/test/test_resource_requirements.py
new file mode 100644
index 0000000..2465e9b
--- /dev/null
+++ b/test/test_resource_requirements.py
@@ -0,0 +1,143 @@
+"""Integration tests for CWL Resource Requirements validation."""
+
+from typing import Optional
+
+import pytest
+from cwl_utils.parser.cwl_v1_2 import CommandLineTool, ExpressionTool, ResourceRequirement, Workflow, WorkflowStep
+
+from dirac_cwl.submission_models import JobSubmissionModel, ProductionSubmissionModel, TransformationSubmissionModel
+
+# -----------------------------------------------------------------------------
+# Helper functions
+# -----------------------------------------------------------------------------
+
+
+def create_commandlinetool(
+    requirements: Optional[list] = None,
+    inputs: Optional[list] = None,
+    outputs: Optional[list] = None,
+) -> CommandLineTool:
+    """Create a CommandLineTool with the given requirements, inputs, and outputs."""
+    return CommandLineTool(
+        requirements=requirements or [],
+        inputs=inputs or [],
+        outputs=outputs or [],
+    )
+
+
+def create_workflow(
+    requirements: Optional[list] = None,
+    steps: Optional[list[WorkflowStep]] = None,
+    inputs: Optional[list] = None,
+    outputs: Optional[list] = None,
+) -> Workflow:
+    """Create a Workflow with the given requirements, steps, inputs, and outputs."""
+    return Workflow(
+        requirements=requirements or [],
+        steps=steps or [],
+        inputs=inputs or [],
+        outputs=outputs or [],
+    )
+
+
+def create_step(
+    requirements: Optional[list] = None,
+    run: Optional[CommandLineTool | Workflow] = None,
+    in_: Optional[list] = None,
+    out: Optional[list] = None,
+) -> WorkflowStep:
+    """Create a WorkflowStep with the given requirements, run, inputs, and outputs."""
+    return WorkflowStep(
+        requirements=requirements or [],
+        run=run,
+        in_=in_ or [],
+        out=out or [],
+    )
+
+
+def create_expressiontool(
+    requirements: Optional[list] = None,
+    inputs: Optional[list] = None,
+    outputs: Optional[list] = None,
+) -> ExpressionTool:
+    """Create an ExpressionTool with the given requirements, inputs, and outputs."""
+    return ExpressionTool(
+        expression="",
+        requirements=requirements or [],
+        inputs=inputs or [],
+        outputs=outputs or [],
+    )
+
+
+def assert_submission_fails(task):
+    """Assert that submission fails with ValueError for Job and Transformation models with bad resource requirements.
+
+    :param: CWL task to submit (Workflow, WorkflowStep, CommandLineTool, etc.)
+    """
+    with pytest.raises(ValueError):
+        JobSubmissionModel(task=task)
+    with pytest.raises(ValueError):
+        TransformationSubmissionModel(task=task)
+    with pytest.raises(ValueError):
+        ProductionSubmissionModel(task=task)
+
+
+# -----------------------------------------------------------------------------
+# Resource requirements tests
+# -----------------------------------------------------------------------------
+@pytest.mark.parametrize(
+    "bad_min_max_reqs",
+    [
+        ResourceRequirement(coresMin=4, coresMax=2),
+        ResourceRequirement(ramMin=2048, ramMax=1024),
+        ResourceRequirement(tmpdirMin=1024, tmpdirMax=512),
+        ResourceRequirement(outdirMin=512, outdirMax=256),
+    ],
+)
+def test_bad_min_max_resource_reqs(bad_min_max_reqs):
+    """Test invalid min/max resource requirements in CWL objects."""
+    # CommandlineTool with bad minmax reqs
+    clt = create_commandlinetool(requirements=[bad_min_max_reqs])
+    assert_submission_fails(clt)
+
+    # ExpressionTool with bad minmax reqs
+    expression_tool = create_expressiontool(requirements=[bad_min_max_reqs])
+    assert_submission_fails(expression_tool)
+
+    # WorkflowStep.run with bad minmax reqs
+    step_bad_run = create_step(run=clt)
+    workflow = create_workflow(steps=[step_bad_run])
+    assert_submission_fails(workflow)
+
+    step_bad_run = create_step(run=expression_tool)
+    workflow = create_workflow(steps=[step_bad_run])
+    assert_submission_fails(workflow)
+
+    # WorkflowStep with bad minmax reqs
+    clt = create_commandlinetool()
+    step = create_step(run=clt, requirements=[bad_min_max_reqs])
+    workflow = create_workflow(steps=[step])
+    assert_submission_fails(workflow)
+
+    expression_tool = create_commandlinetool()
+    step = create_step(run=expression_tool, requirements=[bad_min_max_reqs])
+    workflow = create_workflow(steps=[step])
+    assert_submission_fails(workflow)
+
+    # Workflow with bad minmax reqs
+    workflow = create_workflow(requirements=[bad_min_max_reqs])
+    assert_submission_fails(workflow)
+
+    # NestedWorkflow with bad minmax reqs
+    nest_workflow = create_workflow(requirements=[bad_min_max_reqs])
+    step = create_step(run=nest_workflow)
+    workflow = create_workflow(steps=[step])
+    assert_submission_fails(workflow)
+
+    # DeepNestedWorkflow with bad minmax reqs
+    deep_workflow = create_workflow(requirements=[bad_min_max_reqs])
+    deep_step = create_step(run=deep_workflow)
+    nest_workflow = create_workflow(steps=[deep_step])
+    step = create_step(run=nest_workflow)
+    workflow = create_workflow(steps=[step])
+    assert_submission_fails(workflow)
diff --git a/test/test_workflows.py b/test/test_workflows.py
index 0963908..22d8226 100644
--- a/test/test_workflows.py
+++ b/test/test_workflows.py
@@ -186,7 +186,7 @@ def test_run_job_success(cli_runner, cleanup, pi_test_files, cwl_file, inputs):
         ),
         # The description file points to itself (another circular dependency)
         (
-            "test/workflows/bad_references/reference_circular1.cwl",
+            "test/workflows/bad_references/reference_itself.cwl",
             [],
             "Recursingintostep",
         ),
@@ -463,7 +463,7 @@ def run_and_capture():
         ),
         # The description file points to itself (another circular dependency)
         (
-            "test/workflows/bad_references/reference_circular1.cwl",
+            "test/workflows/bad_references/reference_itself.cwl",
             "Recursingintostep",
         ),
     ],