diff --git a/vlib/builtin/map.v b/vlib/builtin/map.v
index 4528637a6d..d2ca3e59fb 100644
--- a/vlib/builtin/map.v
+++ b/vlib/builtin/map.v
@@ -117,6 +117,23 @@ fn new_dense_array(value_bytes int) DenseArray {
 	}
 }
 
+[inline]
+fn (d &DenseArray) key(i int) voidptr {
+	return unsafe {voidptr(d.keys + i)}
+}
+
+// for cgen
+[inline]
+fn (d &DenseArray) value(i int) voidptr {
+	return unsafe {voidptr(d.values + i * d.value_bytes)}
+}
+
+[inline]
+fn (d &DenseArray) has_index(i int) bool {
+	pkey := unsafe {d.keys + i}
+	return pkey.str != 0
+}
+
 // Push element to array and return index
 // The growth-factor is roughly 1.125 `(x + (x >> 3))`
 [inline]
diff --git a/vlib/v/gen/auto_str_methods.v b/vlib/v/gen/auto_str_methods.v
index d0ba04fc75..0481a6b0d9 100644
--- a/vlib/v/gen/auto_str_methods.v
+++ b/vlib/v/gen/auto_str_methods.v
@@ -258,7 +258,6 @@ fn (mut g Gen) gen_str_for_map(info table.Map, styp string, str_fn_name string)
 	if !val_sym.has_method('str') {
 		g.gen_str_for_type(info.value_type)
 	}
-	zero := g.type_default(info.value_type)
 	g.type_definitions.writeln('static string ${str_fn_name}($styp m); // auto')
 	g.auto_str_funcs.writeln('static string ${str_fn_name}($styp m) { return indent_${str_fn_name}(m, 0);}')
 	g.type_definitions.writeln('static string indent_${str_fn_name}($styp m, int indent_count); // auto')
@@ -266,14 +265,11 @@ fn (mut g Gen) gen_str_for_map(info table.Map, styp string, str_fn_name string)
 	g.auto_str_funcs.writeln('\tstrings__Builder sb = strings__new_builder(m.key_values.len*10);')
 	g.auto_str_funcs.writeln('\tstrings__Builder_write(&sb, _SLIT("{"));')
 	g.auto_str_funcs.writeln('\tfor (unsigned int i = 0; i < m.key_values.len; ++i) {')
-	g.auto_str_funcs.writeln('\t\tif (m.key_values.keys[i].str == 0) { continue; }')
-	g.auto_str_funcs.writeln('\t\tstring key = (*(string*)DenseArray_get(m.key_values, i));')
+	g.auto_str_funcs.writeln('\t\tif (!DenseArray_has_index(&m.key_values, i)) { continue; }')
+	g.auto_str_funcs.writeln('\t\tstring key = *(string*)DenseArray_key(&m.key_values, i);')
 	g.auto_str_funcs.writeln('\t\tstrings__Builder_write(&sb, _STR("\'%.*s\\000\'", 2, key));')
 	g.auto_str_funcs.writeln('\t\tstrings__Builder_write(&sb, _SLIT(": "));')
-	g.auto_str_funcs.write('\t$val_styp it = (*($val_styp*)map_get(')
-	g.auto_str_funcs.write('m, (*(string*)DenseArray_get(m.key_values, i))')
-	g.auto_str_funcs.write(', ')
-	g.auto_str_funcs.writeln(' &($val_styp[]) { $zero }));')
+	g.auto_str_funcs.writeln('\t\t$val_styp it = *($val_styp*)DenseArray_value(&m.key_values, i);')
 	if val_sym.kind == .string {
 		g.auto_str_funcs.writeln('\t\tstrings__Builder_write(&sb, _STR("\'%.*s\\000\'", 2, it));')
 	} else if val_sym.kind == .struct_ && !val_sym.has_method('str') {
diff --git a/vlib/v/gen/cgen.v b/vlib/v/gen/cgen.v
index 4f8b257f25..93010d3e28 100644
--- a/vlib/v/gen/cgen.v
+++ b/vlib/v/gen/cgen.v
@@ -1221,28 +1221,27 @@ fn (mut g Gen) for_in(it ast.ForInStmt) {
 		g.expr(it.cond)
 		g.writeln(';')
 		g.writeln('for (int $idx = 0; $idx < (int)${atmp}.key_values.len; ++$idx) {')
-		g.writeln('\tif (${atmp}.key_values.keys[$idx].str == 0) {continue;}')
+		g.writeln('\tif (!DenseArray_has_index(&${atmp}.key_values, $idx)) {continue;}')
 		if it.key_var != '_' {
 			key_styp := g.typ(it.key_type)
 			key := c_name(it.key_var)
+			g.writeln('\t$key_styp $key = /*key*/ *($key_styp*)DenseArray_key(&${atmp}.key_values, $idx);')
 			// TODO: analyze whether it.key_type has a .clone() method and call .clone() for all types:
 			if it.key_type == table.string_type {
-				g.writeln('\t$key_styp $key = /*key*/ string_clone(${atmp}.key_values.keys[$idx]);')
-			} else {
-				g.writeln('\t$key_styp $key = /*key*/ ${atmp}.key_values.keys[$idx];')
+				g.writeln('\t$key = string_clone($key);')
 			}
 		}
 		if it.val_var != '_' {
 			val_sym := g.table.get_type_symbol(it.val_type)
-			valstr := '(void*)(${atmp}.key_values.values + $idx * (u32)(${atmp}.value_bytes))'
 			if val_sym.kind == .function {
 				g.write('\t')
 				g.write_fn_ptr_decl(val_sym.info as table.FnType, c_name(it.val_var))
-				g.writeln(' = (*(voidptr*)$valstr);')
+				g.write(' = (*(voidptr*)')
 			} else {
 				val_styp := g.typ(it.val_type)
-				g.writeln('\t$val_styp ${c_name(it.val_var)} = (*($val_styp*)$valstr);')
+				g.write('\t$val_styp ${c_name(it.val_var)} = (*($val_styp*)')
 			}
+			g.writeln('DenseArray_value(&${atmp}.key_values, $idx));')
 		}
 		g.stmts(it.stmts)
 		if it.key_type == table.string_type && !g.is_builtin_mod {