diff --git a/.gersemirc b/.gersemirc
new file mode 100644
index 0000000000..4d74cb215a
--- /dev/null
+++ b/.gersemirc
@@ -0,0 +1,11 @@
+# yaml-language-server: $schema=https://raw.githubusercontent.com/BlankSpruce/gersemi/0.24.0/gersemi/configuration.schema.json
+
+# Needed for gersemi to detect custom functions and macros.
+definitions: ["./cmake"]
+disable_formatting: false
+extensions: []
+indent: 4
+line_length: 120
+list_expansion: favour-inlining
+unsafe: false
+warn_about_unknown_commands: true
diff --git a/pyproject.toml b/pyproject.toml
index 13abb08d76..801d034d4e 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -71,3 +71,5 @@ ruff.sequence = ["ruff-main", "ruff-old"]
 black = "black ."
 
 format.sequence = ["black", "ruff-main", "ruff-old"]
+
+cmake-format = "gersemi cmake src --in-place"
diff --git a/src/svgfill/3rdparty/.gersemirc b/src/svgfill/3rdparty/.gersemirc
new file mode 100644
index 0000000000..f64d72913d
--- /dev/null
+++ b/src/svgfill/3rdparty/.gersemirc
@@ -0,0 +1 @@
+disable_formatting: true