diff --git a/src/wikitextprocessor/core.py b/src/wikitextprocessor/core.py
index 6bd96d8..35e2eff 100644
--- a/src/wikitextprocessor/core.py
+++ b/src/wikitextprocessor/core.py
@@ -1522,7 +1522,9 @@ def expander(arg: str) -> str:
                     tname = (
                         tname.strip()
                         .removeprefix("subst:")
+                        .removeprefix("SUBST:")
                         .removeprefix("safesubst:")
+                        .removeprefix("SAFESUBST:")
                     )
 
                     # Check if it is a parser function call