diff --git a/more_math/MaskMathNode.py b/more_math/MaskMathNode.py
new file mode 100644
index 0000000..808c61c
--- /dev/null
+++ b/more_math/MaskMathNode.py
@@ -0,0 +1,71 @@
+from .helper_functions import generate_dim_variables, getIndexTensorAlongDim, eval_tensor_expr, as_tensor
+
+from comfy_api.latest import io
+
+
+from .MathNodeBase import MathNodeBase
+
+
+class MaskMathNode(MathNodeBase):
+    """
+    Enables math expressions on Images.
+
+    Inputs:
+        a, b, c, d: Mask inputs (b, c, d default to zero if not provided)
+        w, x, y, z: Float variables for expressions
+        mask: Expression to apply on input mask
+
+    Outputs:
+        MASK: Result of applying expression to input masks
+    """
+
+    @classmethod
+    def define_schema(cls) -> io.Schema:
+        return io.Schema(
+            node_id="mrmth_MaskMathNode",
+            category="More math",
+            display_name="Mask math",
+            inputs=[
+                io.Mask.Input(id="a"),
+                io.Mask.Input(id="b", optional=True, lazy=True),
+                io.Mask.Input(id="c", optional=True, lazy=True),
+                io.Mask.Input(id="d", optional=True, lazy=True),
+                io.Float.Input(id="w", default=0.0, optional=True, lazy=True, force_input=True),
+                io.Float.Input(id="x", default=0.0, optional=True, lazy=True, force_input=True),
+                io.Float.Input(id="y", default=0.0, optional=True, lazy=True, force_input=True),
+                io.Float.Input(id="z", default=0.0, optional=True, lazy=True, force_input=True),
+                io.String.Input(id="Mask", default="a*(1-w)+b*w", tooltip="Expression to apply on input images"),
+            ],
+            outputs=[
+                io.Mask.Output(),
+            ],
+        )
+
+    @classmethod
+    def execute(cls, Mask, a, b=None, c=None, d=None, w=0.0, x=0.0, y=0.0, z=0.0):
+        a, b, c, d = cls.prepare_inputs(a, b, c, d)
+
+        variables = {
+            "a": a,
+            "b": b,
+            "c": c,
+            "d": d,
+            "w": w,
+            "x": x,
+            "y": y,
+            "z": z,
+            "X": getIndexTensorAlongDim(a, 2),
+            "Y": getIndexTensorAlongDim(a, 1),
+            "B": getIndexTensorAlongDim(a, 0),
+            "batch": getIndexTensorAlongDim(a, 0),
+            "W": a.shape[2],
+            "width": a.shape[2],
+            "H": a.shape[1],
+            "height": a.shape[1],
+            "T": a.shape[0],
+            "batch_count": a.shape[0],
+        } | generate_dim_variables(a)
+
+        result = eval_tensor_expr(Mask, variables, a.shape)
+
+        return (as_tensor(result, a.shape),)
diff --git a/more_math/nodes.py b/more_math/nodes.py
index b6a6676..b4e884b 100644
--- a/more_math/nodes.py
+++ b/more_math/nodes.py
@@ -3,6 +3,7 @@ from .FloatMathNode import FloatMathNode
 from .ConditioningMathNode import ConditioningMathNode
 from .LatentMathNode import LatentMathNode
 from .ImageMathNode import ImageMathNode
+from .MaskMathNode import MaskMathNode
 from .AudioMathNode import AudioMathNode
 from .VideoMathNode import VideoMathNode
 from .ModelMathNode import ModelMathNode
@@ -77,6 +78,7 @@ class MoreMathExtension(ComfyExtension):
             VAEMathNode,
             LatentMathNode,
             ImageMathNode,
+            MaskMathNode,
             FloatMathNode,
             NoiseMathNode,
             IntToFloatNode,