diff --git a/src/compile.c b/src/compile.c
index 68eefd7..57a6255 100644
--- a/src/compile.c
+++ b/src/compile.c
@@ -303,10 +303,28 @@ tmp_ilist(struct compiler *compiler, int line)
     return ilist;
 }
 
+static struct matcher_instruction_list *
+tmp_milist(struct compiler *compiler)
+{
+    struct matcher_instruction_list *milist;
+    if (
+        (milist = apfl_matcher_instructions_new(compiler->gc)) == NULL
+        || !apfl_gc_tmproot_add(
+            compiler->gc,
+            GC_OBJECT_FROM(milist, GC_TYPE_MATCHER_INSTRUCTIONS)
+        )
+    ) {
+        return NULL;
+    }
+
+    return milist;
+}
+
 struct compile_assignable_ilists {
     struct instruction_list *prelude;
     struct instruction_list *newvars;
     struct instruction_list *setvars;
+    struct matcher_instruction_list *matcher;
 };
 
 static bool
@@ -315,7 +333,6 @@ compile_assignable(
     bool local,
     struct apfl_position position,
     struct apfl_expr_assignable *assignable,
-    struct matcher_instruction_list *milist,
     struct compile_assignable_ilists ilists
 );
 
@@ -324,10 +341,9 @@ compile_assignable_var_or_member(
     struct compiler *compiler,
     bool local,
     struct apfl_expr_assignable_var_or_member *var_or_member,
-    struct matcher_instruction_list *milist,
     struct compile_assignable_ilists ilists
 ) {
-    size_t index = milist->capture_count++;
+    size_t index = ilists.matcher->capture_count++;
 
     if (var_or_member->type != APFL_EXPR_ASSIGNABLE_VAR_OR_MEMBER_VAR) {
         compiler->error = apfl_error_simple(APFL_ERR_NOT_IMPLEMENTED); // TODO: Implement me
@@ -346,9 +362,9 @@ compile_assignable_var_or_member(
      *     }
      */
 
-    TRY(milist_ensure_cap(compiler, milist, 2));
-    milist_put_insn(milist, MATCHER_CAPTURE);
-    milist_put_index(milist, index);
+    TRY(milist_ensure_cap(compiler, ilists.matcher, 2));
+    milist_put_insn(ilists.matcher, MATCHER_CAPTURE);
+    milist_put_index(ilists.matcher, index);
 
     TRY(ilist_ensure_cap(compiler, ilists.newvars, 2));
 
@@ -370,20 +386,19 @@ static bool
 compile_assignable_constant(
     struct compiler *compiler,
     struct apfl_expr_const *constant,
-    struct matcher_instruction_list *milist,
     struct compile_assignable_ilists ilists
 ) {
-    size_t index = milist->value_count++;
+    size_t index = ilists.matcher->value_count++;
 
     TRY(compile_constant(compiler, constant, ilists.prelude));
     TRY(ilist_ensure_cap(compiler, ilists.prelude, 2));
     ilist_put_insn(ilists.prelude, INSN_MATCHER_SET_VAL);
     ilist_put_index(ilists.prelude, index);
 
-    TRY(milist_ensure_cap(compiler, milist, 3));
-    milist_put_insn(milist, MATCHER_CHECK_CONST);
-    milist_put_index(milist, index);
-    milist_put_insn(milist, MATCHER_IGNORE);
+    TRY(milist_ensure_cap(compiler, ilists.matcher, 3));
+    milist_put_insn(ilists.matcher, MATCHER_CHECK_CONST);
+    milist_put_index(ilists.matcher, index);
+    milist_put_insn(ilists.matcher, MATCHER_IGNORE);
 
     return true;
 }
@@ -394,21 +409,20 @@ compile_assignable_predicate(
     bool local,
     struct apfl_position position,
     struct apfl_expr_assignable_predicate *predicate,
-    struct matcher_instruction_list *milist,
     struct compile_assignable_ilists ilists
 ) {
-    size_t index = milist->value_count++;
+    size_t index = ilists.matcher->value_count++;
 
     TRY(compile_expr(compiler, predicate->rhs, ilists.prelude));
     TRY(ilist_ensure_cap(compiler, ilists.prelude, 2));
     ilist_put_insn(ilists.prelude, INSN_MATCHER_SET_VAL);
     ilist_put_index(ilists.prelude, index);
 
-    TRY(milist_ensure_cap(compiler, milist, 2));
-    milist_put_insn(milist, MATCHER_CHECK_PRED);
-    milist_put_index(milist, index);
+    TRY(milist_ensure_cap(compiler, ilists.matcher, 2));
+    milist_put_insn(ilists.matcher, MATCHER_CHECK_PRED);
+    milist_put_index(ilists.matcher, index);
 
-    return compile_assignable(compiler, local, position, predicate->lhs, milist, ilists);
+    return compile_assignable(compiler, local, position, predicate->lhs, ilists);
 }
 
 static bool
@@ -417,7 +431,6 @@ compile_assignable_list_expand(
     bool local,
     struct apfl_position position,
     struct apfl_expr_assignable_list *list,
-    struct matcher_instruction_list *milist,
     struct compile_assignable_ilists ilists,
     size_t expand_at
 ) {
@@ -425,8 +438,8 @@ compile_assignable_list_expand(
     struct apfl_expr_assignable_list_item *expand_item = &list->items[expand_at];
     assert(expand_item->expand);
 
-    TRY(milist_ensure_cap(compiler, milist, 1));
-    milist_put_insn(milist, MATCHER_CONTINUE_FROM_END);
+    TRY(milist_ensure_cap(compiler, ilists.matcher, 1));
+    milist_put_insn(ilists.matcher, MATCHER_CONTINUE_FROM_END);
 
     for (size_t i = list->len; i-- > expand_at+1; ) {
         struct apfl_expr_assignable_list_item *item = &list->items[i];
@@ -439,13 +452,13 @@ compile_assignable_list_expand(
             return false;
         }
 
-        TRY(compile_assignable(compiler, local, position, &item->assignable, milist, ilists));
+        TRY(compile_assignable(compiler, local, position, &item->assignable, ilists));
     }
 
-    TRY(milist_ensure_cap(compiler, milist, 1));
-    milist_put_insn(milist, MATCHER_REMAINDING);
+    TRY(milist_ensure_cap(compiler, ilists.matcher, 1));
+    milist_put_insn(ilists.matcher, MATCHER_REMAINDING);
 
-    TRY(compile_assignable(compiler, local, position, &expand_item->assignable, milist, ilists));
+    TRY(compile_assignable(compiler, local, position, &expand_item->assignable, ilists));
 
     return true;
 }
@@ -456,11 +469,10 @@ compile_assignable_list(
     bool local,
     struct apfl_position position,
     struct apfl_expr_assignable_list *list,
-    struct matcher_instruction_list *milist,
     struct compile_assignable_ilists ilists
 ) {
-    TRY(milist_ensure_cap(compiler, milist, 1));
-    milist_put_insn(milist, MATCHER_ENTER_LIST);
+    TRY(milist_ensure_cap(compiler, ilists.matcher, 1));
+    milist_put_insn(ilists.matcher, MATCHER_ENTER_LIST);
 
     for (size_t i = 0; i < list->len; i++) {
         struct apfl_expr_assignable_list_item *item = &list->items[i];
@@ -471,17 +483,16 @@ compile_assignable_list(
                 local,
                 position,
                 list,
-                milist,
                 ilists,
                 i
             );
         }
 
-        TRY(compile_assignable(compiler, local, position, &item->assignable, milist, ilists));
+        TRY(compile_assignable(compiler, local, position, &item->assignable, ilists));
     }
 
-    TRY(milist_ensure_cap(compiler, milist, 1));
-    milist_put_insn(milist, MATCHER_LEAVE_LIST);
+    TRY(milist_ensure_cap(compiler, ilists.matcher, 1));
+    milist_put_insn(ilists.matcher, MATCHER_LEAVE_LIST);
     return true;
 }
 
@@ -491,21 +502,20 @@ compile_assignable(
     bool local,
     struct apfl_position position,
     struct apfl_expr_assignable *assignable,
-    struct matcher_instruction_list *milist,
     struct compile_assignable_ilists ilists
 ) {
     switch (assignable->type) {
     case APFL_EXPR_ASSIGNABLE_VAR_OR_MEMBER:
-        return compile_assignable_var_or_member(compiler, local, &assignable->var_or_member, milist, ilists);
+        return compile_assignable_var_or_member(compiler, local, &assignable->var_or_member, ilists);
     case APFL_EXPR_ASSIGNABLE_CONSTANT:
-        return compile_assignable_constant(compiler, &assignable->constant, milist, ilists);
+        return compile_assignable_constant(compiler, &assignable->constant, ilists);
     case APFL_EXPR_ASSIGNABLE_PREDICATE:
-        return compile_assignable_predicate(compiler, local, position, &assignable->predicate, milist, ilists);
+        return compile_assignable_predicate(compiler, local, position, &assignable->predicate, ilists);
     case APFL_EXPR_ASSIGNABLE_LIST:
-        return compile_assignable_list(compiler, local, position, &assignable->list, milist, ilists);
+        return compile_assignable_list(compiler, local, position, &assignable->list, ilists);
     case APFL_EXPR_ASSIGNABLE_BLANK:
-        TRY(milist_ensure_cap(compiler, milist, 1));
-        milist_put_insn(milist, MATCHER_IGNORE);
+        TRY(milist_ensure_cap(compiler, ilists.matcher, 1));
+        milist_put_insn(ilists.matcher, MATCHER_IGNORE);
         return true;
     }
 
@@ -547,23 +557,18 @@ compile_complex_assignment(
 
     TRY(ilist_ensure_cap(compiler, ilist, 2));
 
-    struct matcher_instruction_list *milist;
-    if ((milist = apfl_matcher_instructions_new(compiler->gc)) == NULL) {
-        compiler->error = apfl_error_simple(APFL_ERR_MALLOC_FAILED);
-        return false;
-    }
-
-    ilist_put_insn(ilist, INSN_MATCHER_LOAD);
-    ilist_put_matcher(ilist, milist);
-
     struct compile_assignable_ilists ilists = {
         .prelude = ilist,
     };
 
+    MALLOC_FAIL_IF_NULL(compiler, (ilists.matcher = tmp_milist(compiler)));
     MALLOC_FAIL_IF_NULL(compiler, (ilists.newvars = tmp_ilist(compiler, position.line)));
     MALLOC_FAIL_IF_NULL(compiler, (ilists.setvars = tmp_ilist(compiler, position.line)));
 
-    TRY(compile_assignable(compiler, assignment->local, position, &assignment->lhs, milist, ilists));
+    ilist_put_insn(ilist, INSN_MATCHER_LOAD);
+    ilist_put_matcher(ilist, ilists.matcher);
+
+    TRY(compile_assignable(compiler, assignment->local, position, &assignment->lhs, ilists));
 
     TRY(concat_ilists(compiler, ilist, ilists.newvars));