diff --git a/src/check_type.cpp b/src/check_type.cpp
index 61ad34133..fe76d65d5 100644
--- a/src/check_type.cpp
+++ b/src/check_type.cpp
@@ -1745,9 +1745,6 @@ Type *check_get_params(CheckerContext *ctx, Scope *scope, Ast *_params, bool *is
 			if (p->flags&FieldFlag_auto_cast) {
 				param->flags |= EntityFlag_AutoCast;
 			}
-			if (p->flags&FieldFlag_const) {
-				param->flags |= EntityFlag_ConstInput;
-			}
 
 			param->state = EntityState_Resolved; // NOTE(bill): This should have be resolved whilst determining it
 			add_entity(ctx->checker, scope, name, param);
diff --git a/src/ir.cpp b/src/ir.cpp
index db6b0166a..83a512d7d 100644
--- a/src/ir.cpp
+++ b/src/ir.cpp
@@ -4737,6 +4737,14 @@ irValue *ir_emit_comp_against_nil(irProcedure *proc, TokenKind op_kind, irValue
 			irValue *cap  = ir_soa_struct_cap(proc, x);
 			return ir_emit_comp(proc, op_kind, cap, v_zero);
 		}
+	} else if (is_type_struct(t) && type_has_nil(t)) {
+		auto args = array_make<irValue *>(heap_allocator(), 2);
+		irValue *lhs = ir_address_from_load_or_generate_local(proc, x);
+		args[0] = ir_emit_conv(proc, lhs, t_rawptr);
+		args[1] = ir_const_int(type_size_of(t));
+		irValue *val = ir_emit_runtime_call(proc, "memory_compare_zero", args);
+		irValue *res = ir_emit_comp(proc, op_kind, val, v_zero);
+		return ir_emit_conv(proc, res, t_bool);
 	}
 	return nullptr;
 }
diff --git a/src/llvm_backend.cpp b/src/llvm_backend.cpp
index 76c662d17..c9cb000b0 100644
--- a/src/llvm_backend.cpp
+++ b/src/llvm_backend.cpp
@@ -8584,6 +8584,14 @@ lbValue lb_emit_comp_against_nil(lbProcedure *p, TokenKind op_kind, lbValue x) {
 				return res;
 			}
 		}
+	} else if (is_type_struct(t) && type_has_nil(t)) {
+		auto args = array_make<lbValue>(heap_allocator(), 2);
+		lbValue lhs = lb_address_from_load_or_generate_local(p, x);
+		args[0] = lb_emit_conv(p, lhs, t_rawptr);
+		args[1] = lb_const_int(p->module, t_int, type_size_of(t));
+		lbValue val = lb_emit_runtime_call(p, "memory_compare_zero", args);
+		lbValue res = lb_emit_comp(p, op_kind, val, lb_const_int(p->module, t_int, 0));
+		return res;
 	}
 	return {};
 }
diff --git a/src/parser.cpp b/src/parser.cpp
index 86900c133..7d794a898 100644
--- a/src/parser.cpp
+++ b/src/parser.cpp
@@ -3127,7 +3127,6 @@ u32 parse_field_prefixes(AstFile *f) {
 	i32 no_alias_count  = 0;
 	i32 c_vararg_count  = 0;
 	i32 auto_cast_count = 0;
-	i32 const_count     = 0;
 
 	for (;;) {
 		FieldPrefixKind kind = is_token_field_prefix(f);
@@ -3145,14 +3144,12 @@ u32 parse_field_prefixes(AstFile *f) {
 		case FieldPrefix_no_alias:  no_alias_count  += 1; advance_token(f); break;
 		case FieldPrefix_c_var_arg: c_vararg_count  += 1; advance_token(f); break;
 		case FieldPrefix_auto_cast: auto_cast_count += 1; advance_token(f); break;
-		case FieldPrefix_const:     const_count     += 1; advance_token(f); break;
 		}
 	}
 	if (using_count     > 1) syntax_error(f->curr_token, "Multiple 'using' in this field list");
 	if (no_alias_count  > 1) syntax_error(f->curr_token, "Multiple '#no_alias' in this field list");
 	if (c_vararg_count  > 1) syntax_error(f->curr_token, "Multiple '#c_vararg' in this field list");
 	if (auto_cast_count > 1) syntax_error(f->curr_token, "Multiple 'auto_cast' in this field list");
-	if (const_count     > 1) syntax_error(f->curr_token, "Multiple '#const' in this field list");
 
 
 	u32 field_flags = 0;
@@ -3160,7 +3157,6 @@ u32 parse_field_prefixes(AstFile *f) {
 	if (no_alias_count  > 0) field_flags |= FieldFlag_no_alias;
 	if (c_vararg_count  > 0) field_flags |= FieldFlag_c_vararg;
 	if (auto_cast_count > 0) field_flags |= FieldFlag_auto_cast;
-	if (const_count     > 0) field_flags |= FieldFlag_const;
 	return field_flags;
 }
 
diff --git a/src/parser.hpp b/src/parser.hpp
index a98060df9..76ba5c04f 100644
--- a/src/parser.hpp
+++ b/src/parser.hpp
@@ -212,13 +212,12 @@ enum FieldFlag {
 	FieldFlag_no_alias  = 1<<2,
 	FieldFlag_c_vararg  = 1<<3,
 	FieldFlag_auto_cast = 1<<4,
-	FieldFlag_const     = 1<<5,
 
 	FieldFlag_Tags = 1<<10,
 
 	FieldFlag_Results   = 1<<16,
 
-	FieldFlag_Signature = FieldFlag_ellipsis|FieldFlag_using|FieldFlag_no_alias|FieldFlag_c_vararg|FieldFlag_auto_cast|FieldFlag_const,
+	FieldFlag_Signature = FieldFlag_ellipsis|FieldFlag_using|FieldFlag_no_alias|FieldFlag_c_vararg|FieldFlag_auto_cast,
 	FieldFlag_Struct    = FieldFlag_using|FieldFlag_Tags,
 };
 
diff --git a/src/types.cpp b/src/types.cpp
index 8395d1097..4372bdd6a 100644
--- a/src/types.cpp
+++ b/src/types.cpp
@@ -1788,7 +1788,6 @@ bool is_type_polymorphic(Type *t, bool or_specialized=false) {
 
 
 bool type_has_undef(Type *t) {
-	// t = base_type(t);
 	return true;
 }