diff --git a/check_source/check_spelling_c_config.py b/check_source/check_spelling_c_config.py
index b3e88665bc879071faed10903e4143c9dec0b0b1..c1278b97687fcae844acc104c323e89d4a71f723 100644
--- a/check_source/check_spelling_c_config.py
+++ b/check_source/check_spelling_c_config.py
@@ -30,6 +30,7 @@ dict_custom = {
     "breaked",
     "completers",
     "confusticate", "confusticated",
+    "customizable",
     "decrement",
     "decrementing",
     "deduplication",
@@ -56,8 +57,8 @@ dict_custom = {
     "polygonization",
     "postprocessed",
     "precalculate",
-    "prepend",
-    "prepends",
+    "prefetch", "prefetching",
+    "prepend", "prepends",
     "probabilistically",
     "rasterize",
     "rasterizing",