diff --git a/src/c/cmpaux.d b/src/c/cmpaux.d
index 186f52f75..503037ec6 100644
--- a/src/c/cmpaux.d
+++ b/src/c/cmpaux.d
@@ -148,7 +148,7 @@ aset_bv(cl_object x, cl_index index, int value)
 void
 cl_throw(cl_object tag)
 {
-  frame_ptr fr = frs_sch_catch(tag);
+  ecl_frame_ptr fr = frs_sch_catch(tag);
   if (fr == NULL)
     FEcontrol_error("THROW: The catch ~S is undefined.", 1, tag);
   unwind(fr);
@@ -157,7 +157,7 @@ cl_throw(cl_object tag)
 void
 cl_return_from(cl_object block_id, cl_object block_name)
 {
-  frame_ptr fr = frs_sch(block_id);
+  ecl_frame_ptr fr = frs_sch(block_id);
   if (fr == NULL)
     FEcontrol_error("RETURN-FROM: The block ~S with id ~S is missing.",
 		    2, block_name, block_id);
@@ -167,7 +167,7 @@ cl_return_from(cl_object block_id, cl_object block_name)
 void
 cl_go(cl_object tag_id, cl_object label)
 {
-  frame_ptr fr = frs_sch(tag_id);
+  ecl_frame_ptr fr = frs_sch(tag_id);
   if (fr == NULL)
     FEcontrol_error("GO: The tagbody ~S is missing.", 1, tag_id);
   VALUES(0)=label;
diff --git a/src/c/gbc-new.d b/src/c/gbc-new.d
index e8a9599c3..c0d83cf2d 100644
--- a/src/c/gbc-new.d
+++ b/src/c/gbc-new.d
@@ -439,7 +439,7 @@ mark_phase(void)
 	register int i;
 	register struct package *pp;
 	register bds_ptr bdp;
-	register frame_ptr frp;
+	register ecl_frame_ptr frp;
 	register ihs_ptr ihsp;
 
 	mark_object(Cnil);
diff --git a/src/c/stacks.d b/src/c/stacks.d
index 2acac73c8..0188e3ac3 100644
--- a/src/c/stacks.d
+++ b/src/c/stacks.d
@@ -254,10 +254,10 @@ frs_overflow(void)		/* used as condition in list.d */
 	FEerror("Frame stack overflow.", 0);
 }
 
-frame_ptr
+ecl_frame_ptr
 _frs_push(register enum fr_class clas, register cl_object val)
 {
-	frame_ptr output = ++cl_env.frs_top;
+	ecl_frame_ptr output = ++cl_env.frs_top;
 	if (output >= cl_env.frs_limit) frs_overflow();
 	output->frs_lex = cl_env.lex_env;
 	output->frs_bds_top = cl_env.bds_top;
@@ -269,7 +269,7 @@ _frs_push(register enum fr_class clas, register cl_object val)
 }
 
 void
-unwind(frame_ptr fr)
+unwind(ecl_frame_ptr fr)
 {
 	cl_env.nlj_fr = fr;
 	while (cl_env.frs_top != fr && cl_env.frs_top->frs_class == FRS_CATCH)
@@ -282,10 +282,10 @@ unwind(frame_ptr fr)
 	/* never reached */
 }
 
-frame_ptr
+ecl_frame_ptr
 frs_sch (cl_object frame_id)
 {
-	frame_ptr top;
+	ecl_frame_ptr top;
 
 	for (top = cl_env.frs_top;  top >= cl_env.frs_org;  top--)
 		if (top->frs_val == frame_id && top->frs_class == FRS_CATCH)
@@ -293,10 +293,10 @@ frs_sch (cl_object frame_id)
 	return(NULL);
 }
 
-frame_ptr
+ecl_frame_ptr
 frs_sch_catch(cl_object frame_id)
 {
-	frame_ptr top;
+	ecl_frame_ptr top;
 
 	for(top = cl_env.frs_top;  top >= cl_env.frs_org  ;top--)
 	  if ((top->frs_val == frame_id && top->frs_class == FRS_CATCH)
@@ -305,10 +305,10 @@ frs_sch_catch(cl_object frame_id)
 	return(NULL);
 }
 
-static frame_ptr
+static ecl_frame_ptr
 get_frame_ptr(cl_object x)
 {
-	frame_ptr p;
+	ecl_frame_ptr p;
 
 	if (FIXNUMP(x)) {
 	  p = cl_env.frs_org + fix(x);
@@ -359,7 +359,7 @@ si_frs_ihs(cl_object arg)
 cl_object
 si_sch_frs_base(cl_object fr, cl_object ihs)
 {
-	frame_ptr x;
+	ecl_frame_ptr x;
 	cl_index y;
 
 	y = fixnnint(ihs);
@@ -403,7 +403,7 @@ init_stacks(int *new_cs_org)
 	cl_index size;
 
 	cl_env.frs_size = size = FRSSIZE + 2*FRSGETA;
-	cl_env.frs_org = (frame_ptr)cl_alloc(size * sizeof(*cl_env.frs_org));
+	cl_env.frs_org = (ecl_frame_ptr)cl_alloc(size * sizeof(*cl_env.frs_org));
 	cl_env.frs_top = cl_env.frs_org-1;
 	cl_env.frs_limit = &cl_env.frs_org[size - 2*FRSGETA];
 	cl_env.bds_size = size = BDSSIZE + 2*BDSGETA;
diff --git a/src/cmp/cmpcatch.lsp b/src/cmp/cmpcatch.lsp
index 421064ced..ae09ce1a1 100644
--- a/src/cmp/cmpcatch.lsp
+++ b/src/cmp/cmpcatch.lsp
@@ -57,7 +57,7 @@
 
 (defun c2unwind-protect (form body)
   (wt-nl "{ volatile bool unwinding = FALSE;")
-  (wt-nl "frame_ptr next_fr; cl_object next_tag;")
+  (wt-nl "ecl_frame_ptr next_fr; cl_object next_tag;")
   ;; Here we compile the form which is protected. When this form
   ;; is aborted, it continues at the frs_pop() with unwinding=TRUE.
   (wt-nl "if (frs_push(FRS_PROTECT,Cnil)) {")
diff --git a/src/h/external.h b/src/h/external.h
index dcae2d8af..1ed61f57c 100644
--- a/src/h/external.h
+++ b/src/h/external.h
@@ -53,10 +53,10 @@ struct cl_env_struct {
 	 * to set return points.
 	 */
 	cl_index frs_size;
-	struct frame *frs_org;
-	struct frame *frs_top;
-	struct frame *frs_limit;
-	struct frame *nlj_fr;
+	struct ecl_frame *frs_org;
+	struct ecl_frame *frs_top;
+	struct ecl_frame *frs_limit;
+	struct ecl_frame *nlj_fr;
 
 	/*
 	 * The following pointers to the C Stack are used to ensure that a
@@ -1215,9 +1215,9 @@ extern cl_object si_reset_stack_limits(void);
 extern void bds_overflow(void) /*__attribute__((noreturn))*/;
 extern void bds_unwind(bds_ptr new_bds_top);
 extern int frs_overflow(void) /*__attribute__((noreturn))*/;
-extern void unwind(frame_ptr fr) /*__attribute__((noreturn))*/;
-extern frame_ptr frs_sch(cl_object frame_id);
-extern frame_ptr frs_sch_catch(cl_object frame_id);
+extern void unwind(ecl_frame_ptr fr) /*__attribute__((noreturn))*/;
+extern ecl_frame_ptr frs_sch(cl_object frame_id);
+extern ecl_frame_ptr frs_sch_catch(cl_object frame_id);
 extern cl_object new_frame_id(void);
 
 /* string.c */
diff --git a/src/h/lwp.h b/src/h/lwp.h
index 7c007db82..86b752087 100644
--- a/src/h/lwp.h
+++ b/src/h/lwp.h
@@ -34,12 +34,12 @@ typedef struct lpd {
 
   /* stacks.h - The Frame stack */
   size_t lwp_frs_size;
-  frame_ptr lwp_frs_org;
-  frame_ptr lwp_frs_limit;
-  frame_ptr lwp_frs_top;
+  ecl_frame_ptr lwp_frs_org;
+  ecl_frame_ptr lwp_frs_limit;
+  ecl_frame_ptr lwp_frs_top;
 
     /* Non-local jumps */
-  frame_ptr lwp_nlj_fr;
+  ecl_frame_ptr lwp_nlj_fr;
   cl_object lwp_nlj_tag;
 
   /* lex.h - Lexical environment */
diff --git a/src/h/stacks.h b/src/h/stacks.h
index 7fbf828a3..c9398700a 100644
--- a/src/h/stacks.h
+++ b/src/h/stacks.h
@@ -112,7 +112,7 @@ enum fr_class {
 	FRS_PROTECT		/* for protect-all */
 };
 
-typedef struct frame {
+typedef struct ecl_frame {
 	jmp_buf		frs_jmpbuf;
 	cl_object	frs_lex;
 	bds_ptr		frs_bds_top;
@@ -120,9 +120,9 @@ typedef struct frame {
 	cl_object	frs_val;
 	ihs_ptr		frs_ihs;
 	cl_index	frs_sp;
-} *frame_ptr;
+} *ecl_frame_ptr;
 
-extern frame_ptr _frs_push(register enum fr_class clas, register cl_object val);
+extern ecl_frame_ptr _frs_push(register enum fr_class clas, register cl_object val);
 
 #define frs_push(class, val)  ecl_setjmp(_frs_push(class, val)->frs_jmpbuf)
 
@@ -176,7 +176,7 @@ cl_env.lex_env ------> ( tag0 value0 tag1 value1 ... )
 	cl_env.lex_env = __env; }
 
 #define CL_UNWIND_PROTECT_BEGIN {\
-	bool __unwinding; frame_ptr __next_fr; \
+	bool __unwinding; ecl_frame_ptr __next_fr; \
 	cl_index __nr; \
 	if (frs_push(FRS_PROTECT,Cnil)) { \
 		__unwinding=1; __next_fr=cl_env.nlj_fr; \