diff --git a/src/build_settings.cpp b/src/build_settings.cpp
index d6cdd7006..b2d6c4f43 100644
--- a/src/build_settings.cpp
+++ b/src/build_settings.cpp
@@ -277,6 +277,8 @@ struct BuildContext {
 	
 	bool copy_file_contents;
 
+	bool disallow_rtti;
+
 	RelocMode reloc_mode;
 	bool disable_red_zone;
 
@@ -946,7 +948,6 @@ void init_build_context(TargetMetrics *cross_target) {
 		}
 	}
 
-	
 	bc->copy_file_contents = true;
 
 	TargetMetrics *metrics = nullptr;
diff --git a/src/check_builtin.cpp b/src/check_builtin.cpp
index eb9d7f293..5561da01b 100644
--- a/src/check_builtin.cpp
+++ b/src/check_builtin.cpp
@@ -1241,6 +1241,10 @@ bool check_builtin_procedure(CheckerContext *c, Operand *operand, Ast *call, i32
 		if (c->scope->flags&ScopeFlag_Global) {
 			compiler_error("'type_info_of' Cannot be declared within the runtime package due to how the internals of the compiler works");
 		}
+		if (build_context.disallow_rtti) {
+			error(call, "'%.*s' has been disallowed", LIT(builtin_name));
+			return false;
+		}
 
 		// NOTE(bill): The type information may not be setup yet
 		init_core_type_info(c->checker);
@@ -1253,9 +1257,9 @@ bool check_builtin_procedure(CheckerContext *c, Operand *operand, Ast *call, i32
 		Type *t = o.type;
 		if (t == nullptr || t == t_invalid || is_type_asm_proc(o.type) || is_type_polymorphic(t)) {
 			if (is_type_polymorphic(t)) {
-				error(ce->args[0], "Invalid argument for 'type_info_of', unspecialized polymorphic type");
+				error(ce->args[0], "Invalid argument for '%.*s', unspecialized polymorphic type", LIT(builtin_name));
 			} else {
-				error(ce->args[0], "Invalid argument for 'type_info_of'");
+				error(ce->args[0], "Invalid argument for '%.*s'", LIT(builtin_name));
 			}
 			return false;
 		}
@@ -1266,7 +1270,7 @@ bool check_builtin_procedure(CheckerContext *c, Operand *operand, Ast *call, i32
 		if (is_operand_value(o) && is_type_typeid(t)) {
 			add_package_dependency(c, "runtime", "__type_info_of");
 		} else if (o.mode != Addressing_Type) {
-			error(expr, "Expected a type or typeid for 'type_info_of'");
+			error(expr, "Expected a type or typeid for '%.*s'", LIT(builtin_name));
 			return false;
 		}
 
@@ -1280,6 +1284,10 @@ bool check_builtin_procedure(CheckerContext *c, Operand *operand, Ast *call, i32
 		if (c->scope->flags&ScopeFlag_Global) {
 			compiler_error("'typeid_of' Cannot be declared within the runtime package due to how the internals of the compiler works");
 		}
+		if (build_context.disallow_rtti) {
+			error(call, "'%.*s' has been disallowed", LIT(builtin_name));
+			return false;
+		}
 
 		// NOTE(bill): The type information may not be setup yet
 		init_core_type_info(c->checker);
@@ -1291,7 +1299,7 @@ bool check_builtin_procedure(CheckerContext *c, Operand *operand, Ast *call, i32
 		}
 		Type *t = o.type;
 		if (t == nullptr || t == t_invalid || is_type_asm_proc(o.type) || is_type_polymorphic(operand->type)) {
-			error(ce->args[0], "Invalid argument for 'typeid_of'");
+			error(ce->args[0], "Invalid argument for '%.*s'", LIT(builtin_name));
 			return false;
 		}
 		t = default_type(t);
@@ -1299,7 +1307,7 @@ bool check_builtin_procedure(CheckerContext *c, Operand *operand, Ast *call, i32
 		add_type_info_type(c, t);
 
 		if (o.mode != Addressing_Type) {
-			error(expr, "Expected a type for 'typeid_of'");
+			error(expr, "Expected a type for '%.*s'", LIT(builtin_name));
 			return false;
 		}
 
diff --git a/src/check_decl.cpp b/src/check_decl.cpp
index 3fdd944f9..b3b1e4474 100644
--- a/src/check_decl.cpp
+++ b/src/check_decl.cpp
@@ -1205,6 +1205,8 @@ void check_global_variable_decl(CheckerContext *ctx, Entity *&e, Ast *type_expr,
 	Operand o = {};
 	check_expr_with_type_hint(ctx, &o, init_expr, e->type);
 	check_init_variable(ctx, e, &o, str_lit("variable declaration"));
+
+	check_rtti_type_disallowed(e->token, e->type, "A variable declaration is using a type, %s, which has been disallowed");
 }
 
 void check_proc_group_decl(CheckerContext *ctx, Entity *&pg_entity, DeclInfo *d) {
diff --git a/src/check_expr.cpp b/src/check_expr.cpp
index e07dc3d60..f1bcb4cd9 100644
--- a/src/check_expr.cpp
+++ b/src/check_expr.cpp
@@ -9352,6 +9352,8 @@ ExprKind check_expr_base(CheckerContext *c, Operand *o, Ast *node, Type *type_hi
 	if (o->type != nullptr && is_type_untyped(o->type)) {
 		add_untyped(c, node, o->mode, o->type, o->value);
 	}
+	check_rtti_type_disallowed(node, o->type, "An expression is using a type, %s, which has been disallowed");
+
 	add_type_and_value(c->info, node, o->mode, o->type, o->value);
 	return kind;
 }
diff --git a/src/check_type.cpp b/src/check_type.cpp
index c2324ee5a..ff2c3d6a6 100644
--- a/src/check_type.cpp
+++ b/src/check_type.cpp
@@ -3031,5 +3031,7 @@ Type *check_type_expr(CheckerContext *ctx, Ast *e, Type *named_type) {
 	}
 	set_base_type(named_type, type);
 
+	check_rtti_type_disallowed(e, type, "Use of a type, %s, which has been disallowed");
+
 	return type;
 }
diff --git a/src/checker.cpp b/src/checker.cpp
index fe1d362fa..e6445d752 100644
--- a/src/checker.cpp
+++ b/src/checker.cpp
@@ -29,6 +29,23 @@ bool is_operand_undef(Operand o) {
 	return o.mode == Addressing_Value && o.type == t_untyped_undef;
 }
 
+bool check_rtti_type_disallowed(Token const &token, Type *type, char const *format) {
+	if (build_context.disallow_rtti && type) {
+		if (is_type_any(type)) {
+			gbString t = type_to_string(type);
+			error(token, format, t);
+			gb_string_free(t);
+			return true;
+		}
+	}
+	return false;
+}
+
+bool check_rtti_type_disallowed(Ast *expr, Type *type, char const *format) {
+	GB_ASSERT(expr != nullptr);
+	return check_rtti_type_disallowed(ast_token(expr), type, format);
+}
+
 void scope_reset(Scope *scope) {
 	if (scope == nullptr) return;
 
@@ -875,7 +892,8 @@ void init_universal(void) {
 
 // Types
 	for (isize i = 0; i < gb_count_of(basic_types); i++) {
-		add_global_type_entity(basic_types[i].Basic.name, &basic_types[i]);
+		String const &name = basic_types[i].Basic.name;
+		add_global_type_entity(name, &basic_types[i]);
 	}
 	add_global_type_entity(str_lit("byte"), &basic_types[Basic_u8]);
 
@@ -977,6 +995,7 @@ void init_universal(void) {
 	add_global_bool_constant("ODIN_TEST",                     bc->command_kind == Command_test);
 	add_global_bool_constant("ODIN_NO_ENTRY_POINT",           bc->no_entry_point);
 	add_global_bool_constant("ODIN_FOREIGN_ERROR_PROCEDURES", bc->ODIN_FOREIGN_ERROR_PROCEDURES);
+	add_global_bool_constant("ODIN_DISALLOW_RTTI",            bc->disallow_rtti);
 
 
 // Builtin Procedures
@@ -1669,6 +1688,10 @@ void add_implicit_entity(CheckerContext *c, Ast *clause, Entity *e) {
 void add_type_info_type(CheckerContext *c, Type *t) {
 	void add_type_info_type_internal(CheckerContext *c, Type *t);
 
+	if (build_context.disallow_rtti) {
+		return;
+	}
+
 	mutex_lock(&c->info->type_info_mutex);
 	add_type_info_type_internal(c, t);
 	mutex_unlock(&c->info->type_info_mutex);
diff --git a/src/llvm_backend.cpp b/src/llvm_backend.cpp
index 6ca256c4b..04c3200f8 100644
--- a/src/llvm_backend.cpp
+++ b/src/llvm_backend.cpp
@@ -1285,7 +1285,11 @@ void lb_generate_code(lbGenerator *gen) {
 		// x86-64-v3: (close to Haswell) AVX, AVX2, BMI1, BMI2, F16C, FMA, LZCNT, MOVBE, XSAVE
 		// x86-64-v4: AVX512F, AVX512BW, AVX512CD, AVX512DQ, AVX512VL
 		if (ODIN_LLVM_MINIMUM_VERSION_12) {
-			llvm_cpu = "x86-64-v2";
+			if (build_context.metrics.os == TargetOs_freestanding) {
+				llvm_cpu = "x86-64";
+			} else {
+				llvm_cpu = "x86-64-v2";
+			}
 		}
 	}
 
diff --git a/src/llvm_backend_expr.cpp b/src/llvm_backend_expr.cpp
index 844deb43c..18b66572d 100644
--- a/src/llvm_backend_expr.cpp
+++ b/src/llvm_backend_expr.cpp
@@ -2809,16 +2809,25 @@ lbValue lb_build_unary_and(lbProcedure *p, Ast *expr) {
 						src_tag = lb_emit_load(p, lb_emit_union_tag_ptr(p, v));
 						dst_tag = lb_const_union_tag(p->module, src_type, dst_type);
 					}
+
+
+					isize arg_count = 6;
+					if (build_context.disallow_rtti) {
+						arg_count = 4;
+					}
+
 					lbValue ok = lb_emit_comp(p, Token_CmpEq, src_tag, dst_tag);
-					auto args = array_make<lbValue>(permanent_allocator(), 6);
+					auto args = array_make<lbValue>(permanent_allocator(), arg_count);
 					args[0] = ok;
 
 					args[1] = lb_find_or_add_entity_string(p->module, get_file_path_string(pos.file_id));
 					args[2] = lb_const_int(p->module, t_i32, pos.line);
 					args[3] = lb_const_int(p->module, t_i32, pos.column);
 
-					args[4] = lb_typeid(p->module, src_type);
-					args[5] = lb_typeid(p->module, dst_type);
+					if (!build_context.disallow_rtti) {
+						args[4] = lb_typeid(p->module, src_type);
+						args[5] = lb_typeid(p->module, dst_type);
+					}
 					lb_emit_runtime_call(p, "type_assertion_check", args);
 				}
 
@@ -2831,6 +2840,8 @@ lbValue lb_build_unary_and(lbProcedure *p, Ast *expr) {
 				}
 				lbValue data_ptr = lb_emit_struct_ev(p, v, 0);
 				if ((p->state_flags & StateFlag_no_type_assert) == 0) {
+					GB_ASSERT(!build_context.disallow_rtti);
+
 					lbValue any_id = lb_emit_struct_ev(p, v, 1);
 
 					lbValue id = lb_typeid(p->module, type);
diff --git a/src/llvm_backend_type.cpp b/src/llvm_backend_type.cpp
index 1d6297164..1aac75f9c 100644
--- a/src/llvm_backend_type.cpp
+++ b/src/llvm_backend_type.cpp
@@ -14,6 +14,8 @@ isize lb_type_info_index(CheckerInfo *info, Type *type, bool err_on_not_found=tr
 }
 
 lbValue lb_typeid(lbModule *m, Type *type) {
+	GB_ASSERT(!build_context.disallow_rtti);
+
 	type = default_type(type);
 
 	u64 id = cast(u64)lb_type_info_index(m->info, type);
diff --git a/src/llvm_backend_utility.cpp b/src/llvm_backend_utility.cpp
index 98b7e07f0..fb52a9bd6 100644
--- a/src/llvm_backend_utility.cpp
+++ b/src/llvm_backend_utility.cpp
@@ -676,17 +676,24 @@ lbValue lb_emit_union_cast(lbProcedure *p, lbValue value, Type *type, TokenPos p
 		// NOTE(bill): Panic on invalid conversion
 		Type *dst_type = tuple->Tuple.variables[0]->type;
 
+		isize arg_count = 7;
+		if (build_context.disallow_rtti) {
+			arg_count = 4;
+		}
+
 		lbValue ok = lb_emit_load(p, lb_emit_struct_ep(p, v.addr, 1));
-		auto args = array_make<lbValue>(permanent_allocator(), 7);
+		auto args = array_make<lbValue>(permanent_allocator(), arg_count);
 		args[0] = ok;
 
 		args[1] = lb_const_string(m, get_file_path_string(pos.file_id));
 		args[2] = lb_const_int(m, t_i32, pos.line);
 		args[3] = lb_const_int(m, t_i32, pos.column);
 
-		args[4] = lb_typeid(m, src_type);
-		args[5] = lb_typeid(m, dst_type);
-		args[6] = lb_emit_conv(p, value_, t_rawptr);
+		if (!build_context.disallow_rtti) {
+			args[4] = lb_typeid(m, src_type);
+			args[5] = lb_typeid(m, dst_type);
+			args[6] = lb_emit_conv(p, value_, t_rawptr);
+		}
 		lb_emit_runtime_call(p, "type_assertion_check2", args);
 
 		return lb_emit_load(p, lb_emit_struct_ep(p, v.addr, 0));
@@ -744,16 +751,23 @@ lbAddr lb_emit_any_cast_addr(lbProcedure *p, lbValue value, Type *type, TokenPos
 	if (!is_tuple) {
 		// NOTE(bill): Panic on invalid conversion
 		lbValue ok = lb_emit_load(p, lb_emit_struct_ep(p, v.addr, 1));
-		auto args = array_make<lbValue>(permanent_allocator(), 7);
+
+		isize arg_count = 7;
+		if (build_context.disallow_rtti) {
+			arg_count = 4;
+		}
+		auto args = array_make<lbValue>(permanent_allocator(), arg_count);
 		args[0] = ok;
 
 		args[1] = lb_const_string(m, get_file_path_string(pos.file_id));
 		args[2] = lb_const_int(m, t_i32, pos.line);
 		args[3] = lb_const_int(m, t_i32, pos.column);
 
-		args[4] = any_typeid;
-		args[5] = dst_typeid;
-		args[6] = lb_emit_struct_ev(p, value, 0);;
+		if (!build_context.disallow_rtti) {
+			args[4] = any_typeid;
+			args[5] = dst_typeid;
+			args[6] = lb_emit_struct_ev(p, value, 0);
+		}
 		lb_emit_runtime_call(p, "type_assertion_check2", args);
 
 		return lb_addr(lb_emit_struct_ep(p, v.addr, 0));
diff --git a/src/main.cpp b/src/main.cpp
index 8f4155d39..d2263f5a7 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -638,6 +638,7 @@ enum BuildFlagKind {
 	BuildFlag_StrictStyle,
 	BuildFlag_StrictStyleInitOnly,
 	BuildFlag_ForeignErrorProcedures,
+	BuildFlag_DisallowRTTI,
 
 	BuildFlag_Compact,
 	BuildFlag_GlobalDefinitions,
@@ -796,6 +797,9 @@ bool parse_build_flags(Array<String> args) {
 	add_flag(&build_flags, BuildFlag_StrictStyleInitOnly,   str_lit("strict-style-init-only"),   BuildFlagParam_None, Command__does_check);
 	add_flag(&build_flags, BuildFlag_ForeignErrorProcedures, str_lit("foreign-error-procedures"), BuildFlagParam_None, Command__does_check);
 
+	add_flag(&build_flags, BuildFlag_DisallowRTTI,            str_lit("disallow-rtti"),              BuildFlagParam_None, Command__does_check);
+
+
 	add_flag(&build_flags, BuildFlag_Compact,           str_lit("compact"),            BuildFlagParam_None, Command_query);
 	add_flag(&build_flags, BuildFlag_GlobalDefinitions, str_lit("global-definitions"), BuildFlagParam_None, Command_query);
 	add_flag(&build_flags, BuildFlag_GoToDefinitions,   str_lit("go-to-definitions"),  BuildFlagParam_None, Command_query);
@@ -1390,6 +1394,9 @@ bool parse_build_flags(Array<String> args) {
 						case BuildFlag_DisallowDo:
 							build_context.disallow_do = true;
 							break;
+						case BuildFlag_DisallowRTTI:
+							build_context.disallow_rtti = true;
+							break;
 						case BuildFlag_DefaultToNilAllocator:
 							build_context.ODIN_DEFAULT_TO_NIL_ALLOCATOR = true;
 							break;