diff --git a/src/avr.c b/src/avr.c
index 3605e518..52022d16 100644
--- a/src/avr.c
+++ b/src/avr.c
@@ -1599,6 +1599,12 @@ Memtable avr_mem_order[100] = {
   {"sib",         MEM_SIB | MEM_READONLY},
 };
 
+// Whether a memory is an exception that shouldn't be there for this particular i/face
+int avr_mem_exclude(const PROGRAMMER *pgm, const AVRPART *p, const AVRMEM *mem) {
+  return // Classic part usersig memories cannot be read/written using ISP
+    mem_is_usersig(mem) && (p->prog_modes&PM_Classic) && (pgm->prog_modes&p->prog_modes&PM_ISP);
+}
+
 int avr_get_mem_type(const char *str) {
   for(size_t i=0; i < sizeof avr_mem_order/sizeof *avr_mem_order; i++) {
     if(avr_mem_order[i].str && str_eq(avr_mem_order[i].str, str))
diff --git a/src/libavrdude.h b/src/libavrdude.h
index 31c5a8e0..ba755f44 100644
--- a/src/libavrdude.h
+++ b/src/libavrdude.h
@@ -1144,6 +1144,8 @@ int avr_get_cycle_count(const PROGRAMMER *pgm, const AVRPART *p, int *cycles);
 
 int avr_put_cycle_count(const PROGRAMMER *pgm, const AVRPART *p, int cycles);
 
+int avr_mem_exclude(const PROGRAMMER *pgm, const AVRPART *p, const AVRMEM *mem);
+
 int avr_get_mem_type(const char *str);
 
 int avr_mem_is_flash_type(const AVRMEM *mem);
diff --git a/src/update.c b/src/update.c
index ab691520..66929a7f 100644
--- a/src/update.c
+++ b/src/update.c
@@ -269,15 +269,9 @@ static void ioerror(const char *iotype, const UPDATE *upd) {
   msg_ext_error("\n");
 }
 
-// Whether a memory is an exception that shouldn't be included
-static int exclude(const PROGRAMMER *pgm, const AVRPART *p, const AVRMEM *mem) {
-  return // Classic part usersig memories cannot be read/written using ISP
-    mem_is_usersig(mem) && (p->prog_modes&PM_Classic) && (pgm->prog_modes&p->prog_modes&PM_ISP);
-}
-
 // Whether a memory should be returned for ALL: exclude IO/SRAM
 static int is_interesting_mem(const PROGRAMMER *pgm, const AVRPART *p, const AVRMEM *mem) {
-  return !mem_is_io(mem) && !mem_is_sram(mem) && !(pgm && exclude(pgm, p, mem));
+  return !mem_is_io(mem) && !mem_is_sram(mem) && !(pgm && avr_mem_exclude(pgm, p, mem));
 }
 
 // Whether a memory should be backup-ed: exclude sub-memories