diff --git a/py/asmarm.c b/py/asmarm.c
index 63963d2c0..56e05cf56 100644
--- a/py/asmarm.c
+++ b/py/asmarm.c
@@ -39,7 +39,7 @@
 #define SIGNED_FIT24(x) (((x) & 0xff800000) == 0) || (((x) & 0xff000000) == 0xff000000)
 
 void asm_arm_end_pass(asm_arm_t *as) {
-    if (as->pass == ASM_ARM_PASS_EMIT) {
+    if (as->base.pass == ASM_ARM_PASS_EMIT) {
 #ifdef __arm__
         // flush I- and D-cache
         asm volatile(
@@ -333,9 +333,9 @@ void asm_arm_strb_reg_reg_reg(asm_arm_t *as, uint rd, uint rm, uint rn) {
 }
 
 void asm_arm_bcc_label(asm_arm_t *as, int cond, uint label) {
-    assert(label < as->max_num_labels);
-    mp_uint_t dest = as->label_offsets[label];
-    mp_int_t rel = dest - as->code_offset;
+    assert(label < as->base.max_num_labels);
+    mp_uint_t dest = as->base.label_offsets[label];
+    mp_int_t rel = dest - as->base.code_offset;
     rel -= 8; // account for instruction prefetch, PC is 8 bytes ahead of this instruction
     rel >>= 2; // in ARM mode the branch target is 32-bit aligned, so the 2 LSB are omitted
 
diff --git a/py/asmx86.c b/py/asmx86.c
index ef315bf43..dd3ad0224 100644
--- a/py/asmx86.c
+++ b/py/asmx86.c
@@ -232,7 +232,7 @@ void asm_x86_mov_i32_to_r32(asm_x86_t *as, int32_t src_i32, int dest_r32) {
 // src_i32 is stored as a full word in the code, and aligned to machine-word boundary
 void asm_x86_mov_i32_to_r32_aligned(asm_x86_t *as, int32_t src_i32, int dest_r32) {
     // mov instruction uses 1 byte for the instruction, before the i32
-    while (((as->code_offset + 1) & (WORD_SIZE - 1)) != 0) {
+    while (((as->base.code_offset + 1) & (WORD_SIZE - 1)) != 0) {
         asm_x86_nop(as);
     }
     asm_x86_mov_i32_to_r32(as, src_i32, dest_r32);
@@ -339,13 +339,13 @@ void asm_x86_setcc_r8(asm_x86_t *as, mp_uint_t jcc_type, int dest_r8) {
 }
 
 STATIC mp_uint_t get_label_dest(asm_x86_t *as, mp_uint_t label) {
-    assert(label < as->max_num_labels);
-    return as->label_offsets[label];
+    assert(label < as->base.max_num_labels);
+    return as->base.label_offsets[label];
 }
 
 void asm_x86_jmp_label(asm_x86_t *as, mp_uint_t label) {
     mp_uint_t dest = get_label_dest(as, label);
-    mp_int_t rel = dest - as->code_offset;
+    mp_int_t rel = dest - as->base.code_offset;
     if (dest != (mp_uint_t)-1 && rel < 0) {
         // is a backwards jump, so we know the size of the jump on the first pass
         // calculate rel assuming 8 bit relative jump
@@ -367,7 +367,7 @@ void asm_x86_jmp_label(asm_x86_t *as, mp_uint_t label) {
 
 void asm_x86_jcc_label(asm_x86_t *as, mp_uint_t jcc_type, mp_uint_t label) {
     mp_uint_t dest = get_label_dest(as, label);
-    mp_int_t rel = dest - as->code_offset;
+    mp_int_t rel = dest - as->base.code_offset;
     if (dest != (mp_uint_t)-1 && rel < 0) {
         // is a backwards jump, so we know the size of the jump on the first pass
         // calculate rel assuming 8 bit relative jump
@@ -499,7 +499,7 @@ void asm_x86_call_ind(asm_x86_t *as, void *ptr, mp_uint_t n_args, int temp_r32)
     // this reduces code size by 2 bytes per call, but doesn't seem to speed it up at all
     /*
     asm_x86_write_byte_1(as, OPCODE_CALL_REL32);
-    asm_x86_write_word32(as, ptr - (void*)(as->code_base + as->code_offset + 4));
+    asm_x86_write_word32(as, ptr - (void*)(as->code_base + as->base.code_offset + 4));
     */
 
     // the caller must clean up the stack