diff --git a/check_source/check_spelling_c_config.py b/check_source/check_spelling_c_config.py
index e95152de5b68f3a434757815f4226769b720a525..ff0c9618eb348507483e9a6e43e132e511548a32 100644
--- a/check_source/check_spelling_c_config.py
+++ b/check_source/check_spelling_c_config.py
@@ -48,6 +48,7 @@ dict_custom = {
     # Correct spelling, update the dictionary, here:
     # https://github.com/en-wl/wordlist
     "adjoint", "adjugate",
+    "alignable",
     "allocator",
     "atomicity",
     "boolean",
@@ -154,6 +155,7 @@ dict_custom = {
     "keymap",
     "lerp",
     "metadata",
+    "mutex",
     "opengl",
     "preprocessor",
     "quantized",