diff --git a/vlib/os/os.v b/vlib/os/os.v
index d7a1e5ac40..ed5009c4f8 100644
--- a/vlib/os/os.v
+++ b/vlib/os/os.v
@@ -48,6 +48,9 @@ pub fn cp_all(src string, dst string, overwrite bool) ? {
 		cp(source_path, adjusted_path) ?
 		return
 	}
+	if !exists(dest_path) {
+		mkdir(dest_path) ?
+	}
 	if !is_dir(dest_path) {
 		return error('Destination path is not a valid directory')
 	}
diff --git a/vlib/os/os_test.v b/vlib/os/os_test.v
index 8078d84681..cface1ebf7 100644
--- a/vlib/os/os_test.v
+++ b/vlib/os/os_test.v
@@ -55,7 +55,7 @@ fn test_open_file_binary() {
 	}
 	mut file := os.open_file(filename, 'wb+', 0o666) or { panic(err) }
 	bytes := hello.bytes()
-	file.write_bytes(bytes.data, bytes.len)
+	unsafe { file.write_bytes(bytes.data, bytes.len) }
 	file.close()
 	assert hello.len == os.file_size(filename)
 	read_hello := os.read_bytes(filename) or { panic('error reading file $filename') }
@@ -144,7 +144,7 @@ fn test_write_and_read_bytes() {
 	}
 	// We use the standard write_bytes function to write the payload and
 	// compare the length of the array with the file size (have to match).
-	file_write.write_bytes(payload.data, 5)
+	unsafe { file_write.write_bytes(payload.data, 5) }
 	file_write.close()
 	assert payload.len == os.file_size(file_name)
 	mut file_read := os.open(os.real_path(file_name)) or {
@@ -269,6 +269,8 @@ fn test_cp_all() {
 	os.cp_all('ex', './', true) or { panic(err) }
 	// regression test for executive runs with overwrite := true
 	os.cp_all('ex', './', true) or { panic(err) }
+	os.cp_all('ex', 'nonexisting', true) or { panic(err) }
+	assert os.exists(os.join_path('nonexisting', 'ex1.txt'))
 }
 
 fn test_realpath() {