diff --git a/libr/core/cmd_anal.c b/libr/core/cmd_anal.c
index b531108643..fdfbaed897 100644
--- a/libr/core/cmd_anal.c
+++ b/libr/core/cmd_anal.c
@@ -1124,6 +1124,17 @@ static void ar_show_help(RCore *core) {
 	r_core_cmd_help (core, help_message);
 }
 
+static void cmd_ara_help(RCore *core) {
+	const char* help_msg[] = {
+		"Usage:", "ara[+-s]", "Register Arena Push/Pop/Swap",
+		"ara", "", "show all register arenas allocated",
+		"ara", "+", "push a new register arena for each type",
+		"ara", "-", "pop last register arena",
+		"aras", "", "swap last two register arenas",
+		NULL };
+	r_core_cmd_help (core, help_msg);
+}
+
 // XXX dup from drp :OOO
 void cmd_anal_reg(RCore *core, const char *str) {
 	int size = 0, i, type = R_REG_TYPE_GPR;
@@ -1158,6 +1169,12 @@ void cmd_anal_reg(RCore *core, const char *str) {
 		break;
 	case 'a': // "ara"
 		switch (str[1]) {
+		case '?':
+			cmd_ara_help (core);
+			break;
+		case 's':
+			r_reg_arena_swap (core->anal->reg, false);
+			break;
 		case '+':
 			r_reg_arena_push (core->anal->reg);
 			break;
diff --git a/libr/include/r_reg.h b/libr/include/r_reg.h
index 34543e0224..88cc769ada 100644
--- a/libr/include/r_reg.h
+++ b/libr/include/r_reg.h
@@ -170,7 +170,7 @@ R_API ut64 r_reg_get_pack(RReg *reg, RRegItem *item, int packidx, int packbits);
 
 /* byte arena */
 R_API ut8* r_reg_get_bytes(RReg *reg, int type, int *size);
-R_API int r_reg_set_bytes(RReg *reg, int type, const ut8* buf, const int len);
+R_API bool r_reg_set_bytes(RReg *reg, int type, const ut8* buf, const int len);
 R_API RRegArena *r_reg_arena_new (int size);
 R_API void r_reg_arena_free(RRegArena* ra);
 R_API int r_reg_fit_arena(RReg *reg);
diff --git a/libr/reg/arena.c b/libr/reg/arena.c
index 71625d578f..b7a6d8a0a9 100644
--- a/libr/reg/arena.c
+++ b/libr/reg/arena.c
@@ -30,7 +30,6 @@ R_API ut8* r_reg_get_bytes(RReg *reg, int type, int *size) {
 		if (size) *size = sz;
 		return buf;
 	}
-
 	if (type < 0 || type > (R_REG_TYPE_LAST-1))
 		return NULL;
 	sz = reg->regset[type].arena->size;
@@ -44,16 +43,16 @@ R_API ut8* r_reg_get_bytes(RReg *reg, int type, int *size) {
 }
 
 /* reduce number of return statements */
-R_API int r_reg_set_bytes(RReg *reg, int type, const ut8* buf, const int len) {
-	int i, ret = R_FALSE;
+R_API bool r_reg_set_bytes(RReg *reg, int type, const ut8* buf, const int len) {
+	int i, ret = false;
 	struct r_reg_set_t *regset;
 	RRegArena *arena;
 	int off = 0;
 	if (len<0 || !buf)
-		return R_FALSE;
+		return false;
 
 	if (type == -1) {
-		ret = R_TRUE;
+		ret = true;
 		/* deserialize ALL register types in a single buffer */
 		for (i=0; i<R_REG_TYPE_LAST; i++) {
 			if (reg->regset[i].arena) {
@@ -72,7 +71,7 @@ R_API int r_reg_set_bytes(RReg *reg, int type, const ut8* buf, const int len) {
 				R_MIN (len-off, arena->size));
 			off += arena->size;
 			if (off>len) {
-				ret = R_FALSE;
+				ret = false;
 				break;
 			}
 		}
@@ -85,7 +84,7 @@ R_API int r_reg_set_bytes(RReg *reg, int type, const ut8* buf, const int len) {
 				arena->bytes = malloc (len);
 				if (!arena->bytes) {
 					arena->size = 0;
-					return R_FALSE;
+					return false;
 				}
 				arena->size = len;
 			}
@@ -96,7 +95,7 @@ R_API int r_reg_set_bytes(RReg *reg, int type, const ut8* buf, const int len) {
 					arena->bytes = buf;
 				} else {
 					eprintf ("Error resizing arena to %d\n", len);
-					return R_FALSE;
+					return false;
 				}
 			}
 			if (arena->bytes) {
@@ -104,8 +103,8 @@ R_API int r_reg_set_bytes(RReg *reg, int type, const ut8* buf, const int len) {
 				//len = R_MIN (len, arena->size);
 				memset (arena->bytes, 0, arena->size);
 				memcpy (arena->bytes, buf, len);
-				ret = R_TRUE;
-			} else ret = R_FALSE;
+				ret = true;
+			} else ret = false;
 		}
 	}
 	return ret;
@@ -191,6 +190,7 @@ R_API void r_reg_arena_swap(RReg *reg, int copy) {
 			void *tmp = ia->data;
 			ia->data = ib->data;
 			ib->data = tmp;
+			reg->regset[i].arena = ia->data;
 		} else {
 			//eprintf ("Cannot pop more\n");
 			break;
@@ -203,8 +203,8 @@ R_API void r_reg_arena_swap(RReg *reg, int copy) {
 }
 
 R_API int r_reg_arena_set(RReg *reg, int n, int copy) {
-// XXX this api should be deprecated
-return false;
+	// XXX this api should be deprecated
+	return false;
 #if 0
 	int i;
 // XXX this shuoldnt be used at all
@@ -238,19 +238,15 @@ return false;
 }
 
 R_API void r_reg_arena_pop(RReg *reg) {
+	RRegArena *a;
 	int i;
 	for (i=0; i<R_REG_TYPE_LAST; i++) {
-		if (r_list_length (reg->regset[i].pool) > 1) {
-			RRegArena *a = r_list_pop (reg->regset[i].pool);
-			a = reg->regset[i].pool->tail->data;
-			if (a) {
-				reg->regset[i].arena = a;
-				//if (!i) { r_print_hexdump (NULL, 0, a->bytes, a->size, 16, 16); }
-			}
-		} else {
-			eprintf ("Cannot pop more\n");
-			break;
-		}
+		if (r_list_length (reg->regset[i].pool) < 2)
+			continue;
+		a = r_list_pop (reg->regset[i].pool);
+		r_reg_arena_free (a);
+		a = reg->regset[i].pool->tail->data;
+		if (a) reg->regset[i].arena = a;
 	}
 }
 
diff --git a/libr/reg/profile.c b/libr/reg/profile.c
index 1da6e28a8e..05c8e38448 100644
--- a/libr/reg/profile.c
+++ b/libr/reg/profile.c
@@ -87,6 +87,8 @@ R_API int r_reg_set_profile_string(RReg *reg, const char *str) {
 	if (reg->reg_profile_str && !strcmp (reg->reg_profile_str, str))
 		return true;
 
+	// we should reset all the arenas before setting the new reg profile
+	r_reg_arena_pop (reg);
 	// Purge the old registers
 	r_reg_free_internal (reg);
 
@@ -157,6 +159,10 @@ R_API int r_reg_set_profile_string(RReg *reg, const char *str) {
 		reg->size += 8 - (reg->size&7);
 	reg->size >>= 3; // bits to bytes (divide by 8)
 	r_reg_fit_arena (reg);
+
+	// dup the last arena to allow regdiffing
+	r_reg_arena_push (reg);
+	// reset arenas
 	return true;
 }