diff --git a/resources/testfragments/super_simple.c3 b/resources/testfragments/super_simple.c3
index 0cab6ecba..a6055f864 100644
--- a/resources/testfragments/super_simple.c3
+++ b/resources/testfragments/super_simple.c3
@@ -148,6 +148,7 @@ typedef Inf as BooInf;
 
 func void enumInferenceTest()
 {
+    OtherError e = OtherError.FOO_BAR;
     Inf x = Inf.A;
     x = BooInf.B;
     x = A;
diff --git a/src/compiler/compiler_internal.h b/src/compiler/compiler_internal.h
index ce522c013..76c17a881 100644
--- a/src/compiler/compiler_internal.h
+++ b/src/compiler/compiler_internal.h
@@ -30,8 +30,6 @@ typedef struct _Expr Expr;
 typedef struct _Module Module;
 typedef struct _Type Type;
 
-typedef bool(*CastFunc)(Expr *, Type *, Type *, Type *, CastType cast_type);
-
 typedef struct _BigInt
 {
 	unsigned digit_count;
@@ -888,14 +886,7 @@ extern Type *type_byte, *type_ushort, *type_uint, *type_ulong, *type_usize;
 extern Type *type_compint, *type_compfloat;
 extern Type *type_c_short, *type_c_int, *type_c_long, *type_c_longlong;
 extern Type *type_c_ushort, *type_c_uint, *type_c_ulong, *type_c_ulonglong;
-
-extern Type t_i8, t_i16, t_i32, t_i64, t_isz, t_ixx;
-extern Type t_u1, t_u8, t_u16, t_u32, t_u64, t_usz, t_uxx;
-extern Type t_f32, t_f64, t_fxx;
-extern Type t_u0, t_str;
-extern Type t_cus, t_cui, t_cul, t_cull;
-extern Type t_cs, t_ci, t_cl, t_cll;
-extern Type t_voidstar;
+extern Type *type_typeid, *type_error;
 
 extern const char *main_name;
 
@@ -1159,7 +1150,7 @@ static inline Type *type_reduced(Type *type)
 {
 	Type *canonical = type->canonical;
 	if (canonical->type_kind == TYPE_ENUM) return canonical->decl->enums.type_info->type->canonical;
-	if (canonical->type_kind == TYPE_ERROR) TODO;
+	if (canonical->type_kind == TYPE_ERROR) return type_error->canonical;
 	return canonical;
 }
 
diff --git a/src/compiler/llvm_codegen.c b/src/compiler/llvm_codegen.c
index f638cfc17..aa22ae8d2 100644
--- a/src/compiler/llvm_codegen.c
+++ b/src/compiler/llvm_codegen.c
@@ -46,7 +46,7 @@ static void gencontext_emit_global_variable_definition(GenContext *context, Decl
 	}
 
 	// TODO fix name
-	decl->var.backend_ref = LLVMAddGlobal(context->module, decl->type->backend_type, decl->name);
+	decl->var.backend_ref = LLVMAddGlobal(context->module, llvm_type(decl->type), decl->name);
 
 	// If read only: LLVMSetGlobalConstant(decl->var.backend_ref, 1);
 
diff --git a/src/compiler/llvm_codegen_expr.c b/src/compiler/llvm_codegen_expr.c
index 866b95d37..f07715644 100644
--- a/src/compiler/llvm_codegen_expr.c
+++ b/src/compiler/llvm_codegen_expr.c
@@ -227,7 +227,7 @@ LLVMValueRef gencontext_emit_unary_expr(GenContext *context, Expr *expr)
 		case UNARYOP_ERROR:
 			FATAL_ERROR("Illegal unary op %s", expr->unary_expr.operator);
 		case UNARYOP_NOT:
-			return LLVMBuildXor(context->builder, gencontext_emit_expr(context, expr->unary_expr.expr), LLVMConstInt(type_bool->backend_type, 1, 0), "not");
+			return LLVMBuildXor(context->builder, gencontext_emit_expr(context, expr->unary_expr.expr), LLVMConstInt(llvm_type(type_bool), 1, 0), "not");
 		case UNARYOP_BITNEG:
 			return LLVMBuildNot(context->builder, gencontext_emit_expr(context, expr->unary_expr.expr), "bnot");
 		case UNARYOP_NEGMOD:
@@ -286,7 +286,7 @@ static LLVMValueRef gencontext_emit_logical_and_or(GenContext *context, Expr *ex
 
 			// Generate phi
 	gencontext_emit_block(context, phi_block);
-	LLVMValueRef phi = LLVMBuildPhi(context->builder, type_bool->backend_type, "val");
+	LLVMValueRef phi = LLVMBuildPhi(context->builder, llvm_type(type_bool), "val");
 
 	// Simplify for LLVM by entering the constants we already know of.
 	LLVMValueRef result_on_skip = LLVMConstInt(LLVMInt1TypeInContext(context->context), op == BINARYOP_AND ? 0 : 1, false);
@@ -616,7 +616,7 @@ LLVMValueRef gencontext_emit_elvis_expr(GenContext *context, Expr *expr)
 
 	// Generate phi
 	gencontext_emit_block(context, phi_block);
-	LLVMValueRef phi = LLVMBuildPhi(context->builder, expr->type->backend_type, "val");
+	LLVMValueRef phi = LLVMBuildPhi(context->builder, llvm_type(expr->type), "val");
 
 	LLVMValueRef logic_values[2] = { lhs, rhs };
 	LLVMBasicBlockRef blocks[2] = { current_block, rhs_block };
@@ -649,20 +649,15 @@ LLVMValueRef gencontext_emit_ternary_expr(GenContext *context, Expr *expr)
 
 	// Generate phi
 	gencontext_emit_block(context, phi_block);
-	LLVMValueRef phi = LLVMBuildPhi(context->builder, expr->type->backend_type, "val");
+	LLVMValueRef phi = LLVMBuildPhi(context->builder, llvm_type(expr->type), "val");
 
-	LLVMValueRef logicValues[2] = { lhs, rhs };
+	LLVMValueRef logic_values[2] = { lhs, rhs };
 	LLVMBasicBlockRef blocks[2] = { lhs_block, rhs_block };
-	LLVMAddIncoming(phi, logicValues, blocks, 2);
+	LLVMAddIncoming(phi, logic_values, blocks, 2);
 
 	return phi;
 }
 
-static LLVMValueRef gencontext_emit_identifier_expr(GenContext *context, Expr *expr)
-{
-	return LLVMBuildLoad2(context->builder, expr->identifier_expr.decl->type->canonical->backend_type,
-			expr->identifier_expr.decl->var.backend_ref, expr->identifier_expr.decl->name);
-}
 
 LLVMValueRef gencontext_emit_const_expr(GenContext *context, Expr *expr)
 {
@@ -696,8 +691,7 @@ LLVMValueRef gencontext_emit_const_expr(GenContext *context, Expr *expr)
 			return global_name;
 		}
 		case TYPE_ERROR:
-			// TODO emit as u128? u64?
-			TODO
+			return LLVMConstInt(llvm_type(type_error), expr->const_expr.error_constant->error_constant.value, false);
 		case TYPE_ENUM:
 			return gencontext_emit_expr(context, expr->const_expr.enum_constant->enum_constant.expr);
 		default:
diff --git a/src/compiler/llvm_codegen_stmt.c b/src/compiler/llvm_codegen_stmt.c
index 92bcc8310..428e1dde6 100644
--- a/src/compiler/llvm_codegen_stmt.c
+++ b/src/compiler/llvm_codegen_stmt.c
@@ -23,7 +23,7 @@ static LLVMValueRef gencontext_emit_decl(GenContext *context, Ast *ast)
 {
 	Decl *decl = ast->declare_stmt;
 
-	decl->var.backend_ref = gencontext_emit_alloca(context, llvm_type(decl->type), decl->name);
+	decl->var.backend_ref = gencontext_emit_alloca(context, llvm_type(type_reduced(decl->type)), decl->name);
 	// TODO NRVO
 	// TODO debug info
 	/*
diff --git a/src/compiler/llvm_codegen_type.c b/src/compiler/llvm_codegen_type.c
index bab92199c..896d6c0c2 100644
--- a/src/compiler/llvm_codegen_type.c
+++ b/src/compiler/llvm_codegen_type.c
@@ -155,18 +155,21 @@ LLVMTypeRef llvm_get_type(LLVMContextRef context, Type *type)
 	{
 		case TYPE_POISONED:
 		case TYPE_META_TYPE:
+		case TYPE_ENUM:
+		case TYPE_ERROR:
 			UNREACHABLE;
 		case TYPE_TYPEDEF:
 			return type->backend_type = llvm_get_type(context, type->canonical);
+		case TYPE_ERROR_UNION:
+		{
+			LLVMTypeRef types[2];
+			types[0] = llvm_get_type(context, type_typeid->canonical);
+			types[1] = llvm_get_type(context, type_error->canonical);
+			return type->backend_type = LLVMStructType(types, 2, false);
+		}
 		case TYPE_STRUCT:
 		case TYPE_UNION:
-		case TYPE_ERROR_UNION:
 			return type->backend_type = llvm_type_from_decl(context, type->decl);
-		case TYPE_ENUM:
-			return type->backend_type = llvm_get_type(context, type->decl->enums.type_info->type);
-		case TYPE_ERROR:
-			// TODO: u128? u64?
-			TODO
 		case TYPE_FUNC:
 			return type->backend_type = llvm_func_type(context, type);
 		case TYPE_VOID:
diff --git a/src/compiler/sema_decls.c b/src/compiler/sema_decls.c
index 78450603c..f0f96ec59 100644
--- a/src/compiler/sema_decls.c
+++ b/src/compiler/sema_decls.c
@@ -31,7 +31,7 @@ static inline bool sema_analyse_error(Context *context __unused, Decl *decl)
 				break;
 			}
 		}
-		constant->error_constant.value = i;
+		constant->error_constant.value = i + 1;
 		constant->resolve_status = RESOLVE_DONE;
 	}
 	return success;
diff --git a/src/compiler/sema_expr.c b/src/compiler/sema_expr.c
index 0473133b7..fdf5541de 100644
--- a/src/compiler/sema_expr.c
+++ b/src/compiler/sema_expr.c
@@ -144,7 +144,7 @@ static inline bool sema_expr_analyse_error_constant(Expr *expr, const char *name
 			expr->type = decl->type;
 			expr->expr_kind = EXPR_CONST;
 			expr->const_expr.kind = TYPE_ERROR;
-			expr->const_expr.error_constant = decl;
+			expr->const_expr.error_constant = error_constant;
 			return true;
 		}
 	}
diff --git a/src/compiler/types.c b/src/compiler/types.c
index c5cf89e77..97477ec91 100644
--- a/src/compiler/types.c
+++ b/src/compiler/types.c
@@ -4,22 +4,29 @@
 
 #include "compiler_internal.h"
 
-Type *type_bool, *type_void, *type_string, *type_voidptr;
-Type *type_float, *type_double;
+static Type t_u0, t_str, t_u1, t_i8, t_i16, t_i32, t_i64, t_ixx;
+static Type t_u8, t_u16, t_u32, t_u64;
+static Type t_f32, t_f64, t_fxx;
+static Type t_usz, t_isz;
+static Type t_cus, t_cui, t_cul, t_cull;
+static Type t_cs, t_ci, t_cl, t_cll;
+static Type t_voidstar, t_typeid;
+static Type t_err;
+
+Type *type_bool = &t_u1;
+Type *type_void = &t_u0;
+Type *type_string = &t_str;
+Type *type_voidptr = &t_voidstar;
+Type *type_float = &t_f32;
+Type *type_double = &t_f64;
+Type *type_error = &t_err;
+Type *type_typeid = &t_typeid;
 Type *type_char, *type_short, *type_int, *type_long, *type_isize;
 Type *type_byte, *type_ushort, *type_uint, *type_ulong, *type_usize;
 Type *type_compint, *type_compfloat;
 Type *type_c_short, *type_c_int, *type_c_long, *type_c_longlong;
 Type *type_c_ushort, *type_c_uint, *type_c_ulong, *type_c_ulonglong;
 
-Type t_u0, t_str;
-Type t_u1, t_i8, t_i16, t_i32, t_i64, t_ixx;
-Type t_u8, t_u16, t_u32, t_u64, t_uxx;
-Type t_f32, t_f64, t_fxx;
-Type t_usz, t_isz;
-Type t_cus, t_cui, t_cul, t_cull;
-Type t_cs, t_ci, t_cl, t_cll;
-Type t_voidstar;
 
 #define META_OFFSET 0
 #define PTR_OFFSET 1
@@ -421,6 +428,9 @@ type_create(#_name, &_shortname, &type_ ## _name, _type, _bits, target->align_mi
 
 	type_create_alias("c_short", &t_cs, &type_c_short, type_signed_int_by_bitsize(target->width_c_short));
 	type_create_alias("c_int", &t_ci, &type_c_int, type_signed_int_by_bitsize(target->width_c_int));
+	// TODO fix error size
+	type_create_alias("error", &t_err, &type_error, type_signed_int_by_bitsize(target->width_c_int));
+	type_create_alias("typeid", &t_typeid, &type_typeid, type_signed_int_by_bitsize(target->width_pointer));
 	type_create_alias("c_long", &t_cl, &type_c_long, type_signed_int_by_bitsize(target->width_c_long));
 	type_create_alias("c_longlong", &t_cll, &type_c_longlong, type_signed_int_by_bitsize(target->width_c_long_long));