diff --git a/src/c/assignment.d b/src/c/assignment.d
index 96f811489..55727b554 100644
--- a/src/c/assignment.d
+++ b/src/c/assignment.d
@@ -57,11 +57,15 @@ si_setf_namep(cl_object arg)
 
 @(defun si::fset (fun def &optional macro pprint)
 	cl_type t;
+	bool mflag;
 @
+	mflag = !Null(macro);
 	if (!SYMBOLP(fun)) {
 		cl_object sym = setf_namep(fun);
 		if (sym == OBJNULL)
 			FEtype_error_symbol(fun);
+		if (mflag)
+			FEerror("Cannot define a macro with name (SETF ~S).", 1, fun);
 		fun = CADR(fun);
 		putprop(fun, sym, @'si::setf-symbol');
 		remprop(fun, @'si::setf-lambda');
@@ -69,13 +73,9 @@ si_setf_namep(cl_object arg)
 		remprop(fun, @'si::setf-update');
 		fun = sym;
 	}
-	if (fun->symbol.isform) {
-		if (fun->symbol.mflag) {
-			if (symbol_value(@'si::*inhibit-macro-special*') != Cnil)
-				fun->symbol.isform = FALSE;
-		} else if (symbol_value(@'si::*inhibit-macro-special*') != Cnil)
-			FEerror("~S, a special form, cannot be redefined.", 1, fun);
-	}
+	if (fun->symbol.isform && !mflag)
+		FEerror("~S, a special form, cannot be redefined as a function.",
+			1, fun);
 	clear_compiler_properties(fun);
 	if (fun->symbol.hpack->pack.locked && SYM_FUN(fun) != OBJNULL)
 	  funcall(3, @'warn', make_simple_string("~S is being redefined."), fun);
@@ -121,13 +121,6 @@ cl_fmakunbound(cl_object sym)
 		cl_fmakunbound(sym1);
 		@(return sym)
 	}
-	if (sym->symbol.isform) {
-	  if (sym->symbol.mflag) {
-	    if (symbol_value(@'si::*inhibit-macro-special*') != Cnil)
-	      sym->symbol.isform = FALSE;
-	  } else if (symbol_value(@'si::*inhibit-macro-special*') != Cnil)
-	    FEerror("~S, a special form, cannot be redefined.", 1, sym);
-	}
 	clear_compiler_properties(sym);
 #ifdef PDE
 	remprop(sym, @'defun');
@@ -143,8 +136,7 @@ void
 clear_compiler_properties(cl_object sym)
 {
 	si_unlink_symbol(sym);
-	if (symbol_value(@'si::*inhibit-macro-special*') != Cnil)
-		(void)funcall(2, @'si::clear-compiler-properties', sym);
+	funcall(2, @'si::clear-compiler-properties', sym);
 }
 
 cl_object
@@ -165,7 +157,6 @@ record_source_pathname(cl_object sym, cl_object def)
 void
 init_assignment(void)
 {
-	SYM_VAL(@'si::*inhibit-macro-special*') = Cnil;
 #ifdef PDE
 	SYM_VAL(@'si::*record-source-pathname-p*') = Cnil;
 #endif
diff --git a/src/c/cfun.d b/src/c/cfun.d
index 063921d94..373f252f1 100644
--- a/src/c/cfun.d
+++ b/src/c/cfun.d
@@ -60,42 +60,22 @@ cl_make_cclosure_va(cl_objectfn self, cl_object env, cl_object block)
 void
 cl_def_c_function(cl_object sym, cl_object (*self)(), int narg)
 {
-	if (!SYMBOLP(sym))
-		FEtype_error_symbol(sym);
-	if (sym->symbol.isform && sym->symbol.mflag)
-		sym->symbol.isform = FALSE;
-	clear_compiler_properties(sym);
-	SYM_FUN(sym) = cl_make_cfun(self, sym, symbol_value(@'si::*cblock*'), narg);
-	sym->symbol.mflag = FALSE;
+	si_fset(2, sym,
+		cl_make_cfun(self, sym, symbol_value(@'si::*cblock*'), narg));
 }
 
 void
 cl_def_c_macro_va(cl_object sym, cl_objectfn self)
 {
-	cl_object cf;
-
-	if (!SYMBOLP(sym))
-		FEtype_error_symbol(sym);
-	if (sym->symbol.isform && sym->symbol.mflag)
-		sym->symbol.isform = FALSE;
-	clear_compiler_properties(sym);
-#ifdef PDE
-	record_source_pathname(sym, @'defmacro');
-#endif
-	SYM_FUN(sym) = cl_make_cfun_va(self, sym, symbol_value(@'si::*cblock*'));
-	sym->symbol.mflag = TRUE;
+	si_fset(3, sym,	cl_make_cfun_va(self, sym, symbol_value(@'si::*cblock*')),
+		Ct);
 }
 
 void
 cl_def_c_function_va(cl_object sym, cl_objectfn self)
 {
-	if (!SYMBOLP(sym))
-		FEtype_error_symbol(sym);
-	if (sym->symbol.isform && sym->symbol.mflag)
-		sym->symbol.isform = FALSE;
-	clear_compiler_properties(sym);
-	SYM_FUN(sym) = cl_make_cfun_va(self, sym, symbol_value(@'si::*cblock*'));
-	sym->symbol.mflag = FALSE;
+	si_fset(2, sym,
+		cl_make_cfun_va(self, sym, symbol_value(@'si::*cblock*')));
 }
 
 cl_object
diff --git a/src/c/macros.d b/src/c/macros.d
index c213378fb..b0eeba6e7 100644
--- a/src/c/macros.d
+++ b/src/c/macros.d
@@ -132,5 +132,4 @@ void
 init_macros(void)
 {
 	SYM_VAL(@'*macroexpand-hook*') = @'funcall';
-	SYM_VAL(@'si::*inhibit-macro-special*') = Cnil;
 }
diff --git a/src/c/symbols_list.h b/src/c/symbols_list.h
index 50017c568..e806f6c34 100644
--- a/src/c/symbols_list.h
+++ b/src/c/symbols_list.h
@@ -920,7 +920,6 @@ cl_symbols[] = {
 {"SI::*IGNORE-ERRORS*", SI_SPECIAL, NULL, -1},
 {"SI::*IGNORE-EOF-ON-TERMINAL-IO*", SI_SPECIAL, NULL, -1},
 {"SI::*INDENT-FORMATTED-OUTPUT*", SI_SPECIAL, NULL, -1},
-{"SI::*INHIBIT-MACRO-SPECIAL*", SI_SPECIAL, NULL, -1},
 {"SI::*INIT-FUNCTION-PREFIX*", SI_SPECIAL, NULL, -1},
 {"SI::*INTERRUPT-ENABLE*", SI_SPECIAL, NULL, 1},
 {"SI::*KEEP-DEFINITIONS*", SI_SPECIAL, NULL, -1},
diff --git a/src/cmp/sysfun.lsp b/src/cmp/sysfun.lsp
index 53275a095..4e5e67c68 100644
--- a/src/cmp/sysfun.lsp
+++ b/src/cmp/sysfun.lsp
@@ -852,7 +852,7 @@ type_of(#0)==t_bitvector"))
 (SI::STRING-TO-OBJECT (T) T)
 (si::STANDARD-READTABLE (T) T)
 (SYMBOL-FUNCTION (T) T NIL NIL
-	:inline-always ((t) t nil t "cl_symbol_function(#0)"))
+	:inline-always ((t) t nil t "symbol_function(#0)"))
 (FBOUNDP (symbol) T nil t)
 (SYMBOL-VALUE (symbol) T)
 (BOUNDP (symbol) T nil t
diff --git a/src/lsp/evalmacros.lsp b/src/lsp/evalmacros.lsp
index 51f514930..1228d05ca 100644
--- a/src/lsp/evalmacros.lsp
+++ b/src/lsp/evalmacros.lsp
@@ -11,7 +11,6 @@
 (si::select-package "SYSTEM")
 
 (eval-when (eval compile) (defun sys:clear-compiler-properties (symbol)))
-(eval-when (eval compile) (setq sys:*inhibit-macro-special* nil))
 
 (defmacro defun (name vl &body body &aux doc-string)
   "Syntax: (defun name lambda-list {decl | doc}* {form}*)
diff --git a/src/lsp/setf.lsp b/src/lsp/setf.lsp
index 1d4e1add3..5dd3ccd65 100644
--- a/src/lsp/setf.lsp
+++ b/src/lsp/setf.lsp
@@ -13,7 +13,6 @@
 (in-package "SYSTEM")
 
 (eval-when (eval compile) (defun sys::clear-compiler-properties (symbol)))
-(eval-when (eval compile) (setq sys:*inhibit-macro-special* nil))
 
 ;;; DEFSETF macro.
 (defmacro defsetf (access-fn &rest rest &aux doc)