diff --git a/src/core/coerce.c b/src/core/coerce.c
index 9498699f56..09d52d90e7 100644
--- a/src/core/coerce.c
+++ b/src/core/coerce.c
@@ -293,11 +293,11 @@ MVMint64 MVM_coerce_simple_intify(MVMThreadContext *tc, MVMObject *obj) {
     }
 }
 
-MVMObject * MVM_radix(MVMThreadContext *tc, MVMint16 radix, MVMString *str, MVMint64 offset, MVMint16 flag) {
+MVMObject * MVM_radix(MVMThreadContext *tc, MVMint64 radix, MVMString *str, MVMint64 offset, MVMint64 flag) {
     MVMObject *result;
     MVMnum64 zvalue = 0.0;
     MVMnum64 zbase  = 1.0;
-    MVMint32 chars  = NUM_GRAPHS(str);
+    MVMint64 chars  = NUM_GRAPHS(str);
     MVMnum64 value  = zvalue;
     MVMnum64 base   = zbase;
     MVMint64   pos  = -1;
diff --git a/src/core/coerce.h b/src/core/coerce.h
index a88a63ee31..0a40eedd65 100644
--- a/src/core/coerce.h
+++ b/src/core/coerce.h
@@ -13,4 +13,4 @@ MVMint64 MVM_coerce_s_i(MVMThreadContext *tc, struct _MVMString *s);
 MVMnum64 MVM_coerce_s_n(MVMThreadContext *tc, struct _MVMString *s);
 void MVM_coerce_smart_numify(MVMThreadContext *tc, MVMObject *obj, MVMRegister *res_reg);
 MVMint64 MVM_coerce_simple_intify(MVMThreadContext *tc, MVMObject *obj);
-MVMObject* MVM_radix(MVMThreadContext *tc, MVMint16 radix, struct _MVMString *str, MVMint64 offset, MVMint16 flag);
\ No newline at end of file
+MVMObject* MVM_radix(MVMThreadContext *tc, MVMint64 radix, struct _MVMString *str, MVMint64 offset, MVMint64 flag);
\ No newline at end of file
diff --git a/src/core/interp.c b/src/core/interp.c
index af9f4dbe8f..3c315f7930 100644
--- a/src/core/interp.c
+++ b/src/core/interp.c
@@ -1277,8 +1277,8 @@ void MVM_interp_run(MVMThreadContext *tc, void (*initial_invoke)(MVMThreadContex
                         break;
                     case MVM_OP_radix:
                         GET_REG(cur_op, 0).o = MVM_radix(tc, 
-                            GET_REG(cur_op, 2).i16, GET_REG(cur_op, 4).s,
-                            GET_REG(cur_op, 6).i64, GET_REG(cur_op, 8).i16);
+                            GET_REG(cur_op, 2).i64, GET_REG(cur_op, 4).s,
+                            GET_REG(cur_op, 6).i64, GET_REG(cur_op, 8).i64);
                         cur_op += 10;
                         break;
                     default: {
@@ -2382,7 +2382,7 @@ void MVM_interp_run(MVMThreadContext *tc, void (*initial_invoke)(MVMThreadContex
                         break;
                     case MVM_OP_attrinited: {
                         MVMObject *obj = GET_REG(cur_op, 2).o;
-                        GET_REG(cur_op, 0).i16 = REPR(obj)->attr_funcs->is_attribute_initialized(tc,
+                        GET_REG(cur_op, 0).i64 = REPR(obj)->attr_funcs->is_attribute_initialized(tc,
                             STABLE(obj), OBJECT_BODY(obj),
                             GET_REG(cur_op, 4).o, GET_REG(cur_op, 6).s, MVM_NO_HINT);
                         cur_op += 8;
diff --git a/src/core/oplist b/src/core/oplist
index 4030b3649b..b3c8c60ce1 100644
--- a/src/core/oplist
+++ b/src/core/oplist
@@ -227,9 +227,6 @@ BANK 2 string
 0x30    lt_s                w(int64) r(str) r(str)
 0x31    le_s                w(int64) r(str) r(str)
 0x32    cmp_s               w(int64) r(str) r(str)
-# XXX: should be 
-# 0x33    radix               w(obj) r(int16) r(str) r(int64) r(int16)
-# after int16 is supported
 0x33    radix               w(obj) r(int64) r(str) r(int64) r(int64)
 
 BANK 3 math
@@ -382,9 +379,6 @@ BANK 4 object
 0x80    bootstrarray        w(obj)
 0x81    hlllist             w(obj)
 0x82    hllhash             w(obj)
-# XXX: should be 
-# 0x83    attrinited          w(int16) r(obj) r(obj) r(str)
-# after int16 is supported
 0x83    attrinited          w(int64) r(obj) r(obj) r(str)
 
 BANK 5 io