diff --git a/Mk/Uses/tcl.mk b/Mk/Uses/tcl.mk
index fe0375921e5d..dd9b7d842d83 100644
--- a/Mk/Uses/tcl.mk
+++ b/Mk/Uses/tcl.mk
@@ -165,7 +165,7 @@ TCL_LIBDIR:=	${LOCALBASE}/lib/tcl${TCL_VER}
 TCL_INCLUDEDIR:=${LOCALBASE}/include/tcl${TCL_VER}
 
 .  if ${_TCLTK_PORT} == "tk"
-TK_VER:=	${_TCLTK_WANTED_VERSION:S/8/8./:s/9/9./}
+TK_VER:=	${_TCLTK_WANTED_VERSION:S/8/8./:S/9/9./}
 TK_SHLIB_VER:=	${_TCLTK_WANTED_VERSION}
 WISH:=		${LOCALBASE}/bin/wish${TCL_VER}
 TK_LIBDIR:=	${LOCALBASE}/lib/tk${TK_VER}