diff --git a/requirements.txt b/requirements.txt
index 0d7823158ba0..69c17460aec6 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -16,5 +16,6 @@ PyYAML == 6.0.3        # for parsing/writing YAML
 oras == 0.2.42         # for OCI stuff in mapper-oci-update
 Jinja2 == 3.1.6        # for templating
 rich == 15.0.0         # for rich text formatting
+Pygments == 2.19.1     # syntax highlighting, required by rich.syntax (imported by lib/tools/patching.py)
 dtschema == 2026.4     # for checking dts files and dt bindings
 yamllint == 1.38.0     # for checking dts files and dt bindings