diff --git a/docs/requirements.txt b/docs/requirements.txt
index 31071f4..f6c73fa 100644
--- a/docs/requirements.txt
+++ b/docs/requirements.txt
@@ -3,7 +3,7 @@ requests
 networkx
 meson
 ninja
-pydotplus
+pydot
 nbsphinx
 nbsphinx_link
 Ipython
diff --git a/pixi.lock b/pixi.lock
index 145d848..7dbde80 100644
--- a/pixi.lock
+++ b/pixi.lock
@@ -224,7 +224,7 @@ environments:
       - conda: https://conda.anaconda.org/conda-forge/noarch/pip-26.2.1-pyh8b19718_0.conda
       - conda: https://conda.anaconda.org/conda-forge/noarch/pluggy-1.6.0-pyhf9edf01_1.conda
       - conda: https://conda.anaconda.org/conda-forge/noarch/py-cpuinfo-9.0.0-pyhd8ed1ab_1.conda
-      - conda: https://conda.anaconda.org/conda-forge/noarch/pydotplus-2.0.2-pyhd8ed1ab_7.conda
+      - conda: https://conda.anaconda.org/conda-forge/noarch/pydot-4.0.1-pyhcf101f3_2.conda
       - conda: https://conda.anaconda.org/conda-forge/noarch/pygments-2.20.0-pyhd8ed1ab_0.conda
       - conda: https://conda.anaconda.org/conda-forge/noarch/pyparsing-3.3.2-pyhcf101f3_0.conda
       - conda: https://conda.anaconda.org/conda-forge/noarch/pysocks-1.7.1-pyha55dd90_7.conda
@@ -442,7 +442,7 @@ environments:
       - conda: https://conda.anaconda.org/conda-forge/noarch/pip-26.2.1-pyh8b19718_0.conda
       - conda: https://conda.anaconda.org/conda-forge/noarch/pluggy-1.6.0-pyhf9edf01_1.conda
       - conda: https://conda.anaconda.org/conda-forge/noarch/py-cpuinfo-9.0.0-pyhd8ed1ab_1.conda
-      - conda: https://conda.anaconda.org/conda-forge/noarch/pydotplus-2.0.2-pyhd8ed1ab_7.conda
+      - conda: https://conda.anaconda.org/conda-forge/noarch/pydot-4.0.1-pyhcf101f3_2.conda
       - conda: https://conda.anaconda.org/conda-forge/noarch/pygments-2.20.0-pyhd8ed1ab_0.conda
       - conda: https://conda.anaconda.org/conda-forge/noarch/pyparsing-3.3.2-pyhcf101f3_0.conda
       - conda: https://conda.anaconda.org/conda-forge/noarch/pysocks-1.7.1-pyha55dd90_7.conda
@@ -507,7 +507,7 @@ environments:
       - conda: https://conda.anaconda.org/conda-forge/noarch/pip-26.2.1-pyh8b19718_0.conda
       - conda: https://conda.anaconda.org/conda-forge/noarch/pluggy-1.6.0-pyhf9edf01_1.conda
       - conda: https://conda.anaconda.org/conda-forge/noarch/py-cpuinfo-9.0.0-pyhd8ed1ab_1.conda
-      - conda: https://conda.anaconda.org/conda-forge/noarch/pydotplus-2.0.2-pyhd8ed1ab_7.conda
+      - conda: https://conda.anaconda.org/conda-forge/noarch/pydot-4.0.1-pyhcf101f3_2.conda
       - conda: https://conda.anaconda.org/conda-forge/noarch/pygments-2.20.0-pyhd8ed1ab_0.conda
       - conda: https://conda.anaconda.org/conda-forge/noarch/pyparsing-3.3.2-pyhcf101f3_0.conda
       - conda: https://conda.anaconda.org/conda-forge/noarch/pysocks-1.7.1-pyha55dd90_7.conda
@@ -682,7 +682,7 @@ environments:
       - conda: https://conda.anaconda.org/conda-forge/noarch/pip-26.2.1-pyh8b19718_0.conda
       - conda: https://conda.anaconda.org/conda-forge/noarch/pluggy-1.6.0-pyhf9edf01_1.conda
       - conda: https://conda.anaconda.org/conda-forge/noarch/py-cpuinfo-9.0.0-pyhd8ed1ab_1.conda
-      - conda: https://conda.anaconda.org/conda-forge/noarch/pydotplus-2.0.2-pyhd8ed1ab_7.conda
+      - conda: https://conda.anaconda.org/conda-forge/noarch/pydot-4.0.1-pyhcf101f3_2.conda
       - conda: https://conda.anaconda.org/conda-forge/noarch/pygments-2.20.0-pyhd8ed1ab_0.conda
       - conda: https://conda.anaconda.org/conda-forge/noarch/pyparsing-3.3.2-pyhcf101f3_0.conda
       - conda: https://conda.anaconda.org/conda-forge/noarch/pysocks-1.7.1-pyha55dd90_7.conda
@@ -858,7 +858,7 @@ environments:
       - conda: https://conda.anaconda.org/conda-forge/noarch/pip-26.2.1-pyh8b19718_0.conda
       - conda: https://conda.anaconda.org/conda-forge/noarch/pluggy-1.6.0-pyhf9edf01_1.conda
       - conda: https://conda.anaconda.org/conda-forge/noarch/py-cpuinfo-9.0.0-pyhd8ed1ab_1.conda
-      - conda: https://conda.anaconda.org/conda-forge/noarch/pydotplus-2.0.2-pyhd8ed1ab_7.conda
+      - conda: https://conda.anaconda.org/conda-forge/noarch/pydot-4.0.1-pyhcf101f3_2.conda
       - conda: https://conda.anaconda.org/conda-forge/noarch/pygments-2.20.0-pyhd8ed1ab_0.conda
       - conda: https://conda.anaconda.org/conda-forge/noarch/pyparsing-3.3.2-pyhcf101f3_0.conda
       - conda: https://conda.anaconda.org/conda-forge/noarch/pysocks-1.7.1-pyh09c184e_7.conda
@@ -1184,7 +1184,7 @@ environments:
       - conda: https://conda.anaconda.org/conda-forge/noarch/pluggy-1.6.0-pyhd8ed1ab_0.conda
       - conda: https://conda.anaconda.org/conda-forge/noarch/py-cpuinfo-9.0.0-pyhd8ed1ab_1.conda
       - conda: https://conda.anaconda.org/conda-forge/noarch/pycparser-2.22-pyh29332c3_1.conda
-      - conda: https://conda.anaconda.org/conda-forge/noarch/pydotplus-2.0.2-pyhd8ed1ab_7.conda
+      - conda: https://conda.anaconda.org/conda-forge/noarch/pydot-4.0.1-pyhcf101f3_2.conda
       - conda: https://conda.anaconda.org/conda-forge/noarch/pygments-2.19.2-pyhd8ed1ab_0.conda
       - conda: https://conda.anaconda.org/conda-forge/noarch/pyparsing-3.2.5-pyhcf101f3_0.conda
       - conda: https://conda.anaconda.org/conda-forge/noarch/pysocks-1.7.1-pyha55dd90_7.conda
@@ -1391,7 +1391,7 @@ environments:
       - conda: https://conda.anaconda.org/conda-forge/noarch/pluggy-1.6.0-pyhd8ed1ab_0.conda
       - conda: https://conda.anaconda.org/conda-forge/noarch/py-cpuinfo-9.0.0-pyhd8ed1ab_1.conda
       - conda: https://conda.anaconda.org/conda-forge/noarch/pycparser-2.22-pyh29332c3_1.conda
-      - conda: https://conda.anaconda.org/conda-forge/noarch/pydotplus-2.0.2-pyhd8ed1ab_7.conda
+      - conda: https://conda.anaconda.org/conda-forge/noarch/pydot-4.0.1-pyhcf101f3_2.conda
       - conda: https://conda.anaconda.org/conda-forge/noarch/pygments-2.19.2-pyhd8ed1ab_0.conda
       - conda: https://conda.anaconda.org/conda-forge/noarch/pyparsing-3.2.5-pyhcf101f3_0.conda
       - conda: https://conda.anaconda.org/conda-forge/noarch/pysocks-1.7.1-pyha55dd90_7.conda
@@ -1452,7 +1452,7 @@ environments:
       - conda: https://conda.anaconda.org/conda-forge/noarch/pluggy-1.6.0-pyhd8ed1ab_0.conda
       - conda: https://conda.anaconda.org/conda-forge/noarch/py-cpuinfo-9.0.0-pyhd8ed1ab_1.conda
       - conda: https://conda.anaconda.org/conda-forge/noarch/pycparser-2.22-pyh29332c3_1.conda
-      - conda: https://conda.anaconda.org/conda-forge/noarch/pydotplus-2.0.2-pyhd8ed1ab_7.conda
+      - conda: https://conda.anaconda.org/conda-forge/noarch/pydot-4.0.1-pyhcf101f3_2.conda
       - conda: https://conda.anaconda.org/conda-forge/noarch/pygments-2.19.2-pyhd8ed1ab_0.conda
       - conda: https://conda.anaconda.org/conda-forge/noarch/pyparsing-3.2.5-pyhcf101f3_0.conda
       - conda: https://conda.anaconda.org/conda-forge/noarch/pysocks-1.7.1-pyha55dd90_7.conda
@@ -1597,7 +1597,7 @@ environments:
       - conda: https://conda.anaconda.org/conda-forge/noarch/pluggy-1.6.0-pyhd8ed1ab_0.conda
       - conda: https://conda.anaconda.org/conda-forge/noarch/py-cpuinfo-9.0.0-pyhd8ed1ab_1.conda
       - conda: https://conda.anaconda.org/conda-forge/noarch/pycparser-2.22-pyh29332c3_1.conda
-      - conda: https://conda.anaconda.org/conda-forge/noarch/pydotplus-2.0.2-pyhd8ed1ab_7.conda
+      - conda: https://conda.anaconda.org/conda-forge/noarch/pydot-4.0.1-pyhcf101f3_2.conda
       - conda: https://conda.anaconda.org/conda-forge/noarch/pygments-2.19.2-pyhd8ed1ab_0.conda
       - conda: https://conda.anaconda.org/conda-forge/noarch/pyparsing-3.2.5-pyhcf101f3_0.conda
       - conda: https://conda.anaconda.org/conda-forge/noarch/pysocks-1.7.1-pyha55dd90_7.conda
@@ -1741,7 +1741,7 @@ environments:
       - conda: https://conda.anaconda.org/conda-forge/noarch/pluggy-1.6.0-pyhd8ed1ab_0.conda
       - conda: https://conda.anaconda.org/conda-forge/noarch/py-cpuinfo-9.0.0-pyhd8ed1ab_1.conda
       - conda: https://conda.anaconda.org/conda-forge/noarch/pycparser-2.22-pyh29332c3_1.conda
-      - conda: https://conda.anaconda.org/conda-forge/noarch/pydotplus-2.0.2-pyhd8ed1ab_7.conda
+      - conda: https://conda.anaconda.org/conda-forge/noarch/pydot-4.0.1-pyhcf101f3_2.conda
       - conda: https://conda.anaconda.org/conda-forge/noarch/pygments-2.19.2-pyhd8ed1ab_0.conda
       - conda: https://conda.anaconda.org/conda-forge/noarch/pyparsing-3.2.5-pyhcf101f3_0.conda
       - conda: https://conda.anaconda.org/conda-forge/noarch/pysocks-1.7.1-pyh09c184e_7.conda
@@ -9146,18 +9146,19 @@ packages:
   license_family: BSD
   size: 110100
   timestamp: 1733195786147
-- conda: https://conda.anaconda.org/conda-forge/noarch/pydotplus-2.0.2-pyhd8ed1ab_7.conda
-  sha256: e6681723a8383bf4caaadde22a595289748c6ff909ecbd01c36fbc3b168f41e0
-  md5: 26e4ff85fd62f32f1818b57363995bc6
+- conda: https://conda.anaconda.org/conda-forge/noarch/pydot-4.0.1-pyhcf101f3_2.conda
+  sha256: af7213a8ca077895e7e10c8f33d5de3436b8a26828422e8a113cc59c9277a3e2
+  md5: 15f6d0866b0997c5302fc230a566bc72
   depends:
-  - graphviz
-  - pyparsing >=2.0.1
-  - python >=3.9
+  - graphviz >=2.38.0
+  - pyparsing >=3.1.0
+  - python >=3.10
+  - python
   license: MIT
   license_family: MIT
   run_exports: {}
-  size: 26425
-  timestamp: 1734535829892
+  size: 150656
+  timestamp: 1766345630713
 - conda: https://conda.anaconda.org/conda-forge/noarch/pygments-2.19.2-pyhd8ed1ab_0.conda
   sha256: 5577623b9f6685ece2697c6eb7511b4c9ac5fb607c9babc2646c811b428fd46a
   md5: 6b6ece66ebcae2d5f326c77ef2c5a066
diff --git a/pixi.toml b/pixi.toml
index e049dec..f199fba 100644
--- a/pixi.toml
+++ b/pixi.toml
@@ -20,7 +20,7 @@ networkx = "*"
 ninja = "*"
 numpy = ">=1.20.3,<3"
 pip = "*"
-pydotplus = "*"
+pydot = "*"
 pytest = "!=8.1.0"
 pytest-benchmark = "*"
 pytest-cov = "*"
diff --git a/pymake/plot/__init__.py b/pymake/plot/__init__.py
index b1e9bf9..d8ee85b 100644
--- a/pymake/plot/__init__.py
+++ b/pymake/plot/__init__.py
@@ -1,3 +1,4 @@
 """Functions to plot source code dependencies determined using a directed
-acyclic graph (DAG). pydotplus is used to plot the DAG.
+acyclic graph (DAG). pydot, which is an optional dependency, is used to
+plot the DAG.
 """
diff --git a/pymake/plot/dependency_graphs.py b/pymake/plot/dependency_graphs.py
index cd3d937..0c691bd 100644
--- a/pymake/plot/dependency_graphs.py
+++ b/pymake/plot/dependency_graphs.py
@@ -21,14 +21,26 @@
 
 from pathlib import Path
 
-import pydotplus.graphviz as pydot
-
 from ..utils._compiler_language_files import (
     _get_ordered_srcfiles,
     _get_srcfiles,
 )
 from ..utils._dag import _get_f_nodelist
 
+try:
+    import pydot
+except ImportError:
+    pydot = None
+
+
+def _check_pydot():
+    """Raise an error if pydot, which is an optional dependency, is missing."""
+    if pydot is None:
+        raise ImportError(
+            "pydot is required to plot dependency graphs, install it with "
+            "'pip install mfpymake[plot]'"
+        )
+
 
 def to_pydot(dag, filename="mygraph.png"):
     """Create a png file of a Directed Acyclic Graph.
@@ -44,6 +56,8 @@ def to_pydot(dag, filename="mygraph.png"):
     -------
 
     """
+    _check_pydot()
+
     # Create the graph
     graph = pydot.Dot(graph_type="digraph")
 
@@ -156,6 +170,8 @@ def make_plots(
     -------
 
     """
+    _check_pydot()
+
     srcfiles = _get_ordered_srcfiles(_get_srcfiles(srcdir, include_subdir))
     nodelist = _get_f_nodelist(srcfiles)
     for idx, n in enumerate(nodelist):
diff --git a/pyproject.toml b/pyproject.toml
index 3224e7b..b33162d 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -32,17 +32,19 @@ dependencies = [
     "networkx",
     "meson>=1.3.1",
     "ninja",
-    "pydotplus",
 ]
 dynamic = ["version"]
 
 [project.optional-dependencies]
+plot = [
+    "pydot",
+]
 lint = [
     "cffconvert",
     "ruff",
 ]
 test = [
-    "mfpymake[lint]",
+    "mfpymake[lint,plot]",
     "coverage!=7.6.5",
     "flaky",
     "filelock",