Living in Guidonia Montecelio
Guidonia Montecelio is a city in Italy. At the start of 2026, the foreign population was 11,529. At the start of 2026, the city covers 79.85 km², with a population density of 1,119.9 people per km².
Higher unemployment than 68% of Italian cities that publish it and cleaner air than 94% of Italian cities that publish it.
Which Italy-wide rules apply when you move to Guidonia Montecelio?
National rules stay on the country page instead of being relabelled as city data.
Housing and cost
How much does it cost to rent in Guidonia Montecelio?
Average net cold rent is 7.5 EUR/m² per month (2025-S2), excluding heating and operating charges.
Published average over existing tenancies; a specific flat can sit either side of it. Asking-rent series, where present, are separate rows in the table.
- Average net rent (nettokalt): 7.5 EUR/m²/month · Collected source1
City-level rent is published below; no city-level cost-of-living basket is published for Guidonia Montecelio yet.
| Metric | Value | Period | Source |
|---|---|---|---|
| Dwellings | 40,250 dwellings | 31 Dec 2021 | Istat (Italian National Institute of Statistics)7Official |
| G05 Main Residential Dwellings | 35,472 dwellings | 31 Dec 2021 | Istat (Italian National Institute of Statistics)8Official |
| Average net rent (nettokalt) | 7.5 EUR/m²/month | 31 Dec 2025 | Collected source1Official · municipality zone median |
Worked out from these numbers
What does a 60 m² flat cost?
About 450 EUR a month in cold rent at the published average of 7.5 EUR/m² per month, before heating and operating charges.
Heating, water and operating charges come on top, and a specific flat can sit either side of an average.
Work and income
What is the unemployment rate in Guidonia Montecelio?
The unemployment rate is about 9.4 % (2023).
- Unemployment rate: 9.38 % · Eurostat3
Unemployment rate (%)
Public employment service
No exact public employment office is currently linked to Guidonia Montecelio. The verified national service may still offer online registration, job search or an official office finder.
Centri per l'impiego — Public employment service
Country-level service information is not treated as proof of a physical office in Guidonia Montecelio. Sources checked through 10 Aug 2026.
Family and education
Mobility and administration
Language courses and integration
No exact city-level course record is currently published for Guidonia Montecelio. These verified national programmes may still apply; use the official programme page to check local availability.
CPIA public Italian-language and orientation courses for foreign adults — State Language Course
Italian public adult-education system — Centri Provinciali per l'Istruzione degli Adulti
For foreign adults, people seeking Italian language and culture courses.
L.O.R.R. — Language, Orientation, Recognition and Networks with CPIA — Job-related language course
Italian Ministry of Labour and Social Policies / FAMI 2021-2027 programme
For third-country nationals, vulnerable migrants, unaccompanied minors.
Climate and air quality
Is the air quality good in Guidonia Montecelio?
The annual PM2.5 mean is 9 µg/m³ (2024) — above the WHO 2021 guideline of 5 µg/m³ but within the EU limit of 25 µg/m³. Source: European Environment Agency2
Annual mean at the measuring site(s) serving the city; current-day readings differ.
City values from the published air-quality observations. WHO 2021 guidelines and EU limit values are published constants.
Annual PM2.5 (µg/m³)
| Metric | Value | Period | Source |
|---|---|---|---|
| PM2.5 — annual mean | 9 µg/m³country median 14.0 | 31 Dec 2024 | European Environment Agency2Official |
| Average daytime high by month | Jan 13.22 · Feb 14.3 · Mar 17.29 · Apr 20.47 · May 25.02 · Jun 29.75 · Jul 33.05 · Aug 33.47 · Sep 28.07 · Oct 23.32 · Nov 17.87 · Dec 14.01 °C | 31 Dec 1991 | World Meteorological Organization / NOAA NCEI22Official |
| Average night-time low by month | Jan 2.4 · Feb 2.6 · Mar 5.13 · Apr 7.71 · May 11.79 · Jun 15.57 · Jul 18 · Aug 18.43 · Sep 14.88 · Oct 11.32 · Nov 7.42 · Dec 3.5 °C | 31 Dec 1991 | World Meteorological Organization / NOAA NCEI23Official |
| Average temperature by month | Jan 7.8 · Feb 8.45 · Mar 11.21 · Apr 14.09 · May 18.41 · Jun 22.66 · Jul 25.52 · Aug 25.95 · Sep 21.47 · Oct 17.32 · Nov 12.6 · Dec 8.75 °C | 31 Dec 1991 | World Meteorological Organization / NOAA NCEI24Official |
| Average precipitation by month | Jan 64.1 · Feb 107.3 · Mar 70.62 · Apr 83.72 · May 82.81 · Jun 53.13 · Jul 39.24 · Aug 33.23 · Sep 119.6 · Oct 129.2 · Nov 127.4 · Dec 94.57 mm | 31 Dec 1991 | World Meteorological Organization / NOAA NCEI25Official |
| Average sunshine by month | Jan 155.9 · Feb 171.9 · Mar 203.1 · Apr 221.1 · May 276.5 · Jun 298.8 · Jul 337.6 · Aug 320.2 · Sep 237.9 · Oct 200.6 · Nov 153.3 · Dec 146.9 hours | 31 Dec 1991 | World Meteorological Organization / NOAA NCEI26Official |
Annual PM2.5 fell 43.8% between 2013 and 2024, from 16.0 to 9.0.
Cities of a similar size in Italy
Closest published populations, for a like-for-like comparison.
Population and city profile
How many people live in Guidonia Montecelio?
The published population was 89,011 people in 2025. Source: ISTAT municipality population and citizenship tables 202512
Calculated from the population and foreign-resident facts on this page.
| Metric | Value | Period | Source |
|---|---|---|---|
| Cars per 1,000 residents | 652.1 cars per 1000 people | 31 Dec 2024 | Eurostat4Official |
| City area | 79.85 km² | 2026 | Official SITUAS report 74 (Comuni - Dimensione): exact municipality surface in km2, with annual area vintage.17Official |
| Foreign-resident share | 13.9 % | 31 Dec 2025 | Eurostat5Official |
| Foreign residents | 11,529 people | 1 Jan 2026 | Official ISTAT STRASA estimate of resident foreign population by municipality at 1 January 2026; Età=999 is the total.16Official |
| Population density | 1,120 people/km² | 1 Jan 2026 | Official SITUAS report 74 (Comuni - Dimensione): exact municipality surface in km2, with annual area vintage.18Official |
| Population Female | 44,882 people | 31 Dec 2024 | Istat (Italian National Institute of Statistics)6Official |
| Population Male | 44,129 people | 31 Dec 2024 | Istat (Italian National Institute of Statistics)6Official |
| Population | 89,011 people | 1 Jan 2025 | ISTAT municipality population and citizenship tables 202512Official |
Population rose 2.2% between 2018 and 2025, from 87,073 to 89,011.
International community in Guidonia Montecelio
Named groups from exact city-grain official distributions. Citizenship, birthplace, language and ancestry answer different questions and stay separate.
Country of birth
Resident population in Italy at 1 January 2025; source-native country dimension; total sex · 2025-01-01
| Published group | People | Share |
|---|---|---|
| Derived source total (sum of all published country rows) | 89,011 | 100.0% |
| Italia | 77,294 | 86.8% |
| Romania | 5,000 | 5.6% |
| Egitto | 756 | 0.8% |
| Albania | 346 | 0.4% |
| Bangladesh | 344 | 0.4% |
| Perù | 328 | 0.4% |
| Moldova | 271 | 0.3% |
| Ucraina | 249 | 0.3% |
| Cina | 235 | 0.3% |
Show 123 more groups
| Published group | People | Share |
|---|---|---|
| Marocco | 224 | 0.3% |
| Polonia | 208 | 0.2% |
| Tunisia | 171 | 0.2% |
| Germania | 158 | 0.2% |
| Nigeria | 158 | 0.2% |
| Brasile | 153 | 0.2% |
| Svizzera | 143 | 0.2% |
| Etiopia | 127 | 0.1% |
| Francia | 122 | 0.1% |
| Pakistan | 119 | 0.1% |
| Argentina | 112 | 0.1% |
| Somalia | 104 | 0.1% |
| Regno Unito | 94 | 0.1% |
| India | 90 | 0.1% |
| Ghana | 88 | 0.1% |
| Colombia | 84 | 0.1% |
| Ecuador | 84 | 0.1% |
| Cuba | 82 | 0.1% |
| Libia | 78 | 0.1% |
| Eritrea | 78 | 0.1% |
| Venezuela | 75 | 0.1% |
| Filippine | 73 | 0.1% |
| Federazione russa | 72 | 0.1% |
| Algeria | 72 | 0.1% |
| Macedonia del Nord | 64 | 0.1% |
| Spagna | 57 | 0.1% |
| Stati Uniti d'America | 52 | 0.1% |
| Afghanistan | 51 | 0.1% |
| Burkina Faso | 50 | 0.1% |
| Sri Lanka | 47 | 0.1% |
| Iran | 46 | 0.1% |
| Repubblica Dominicana | 44 | 0.0% |
| Iraq | 42 | 0.0% |
| Bulgaria | 41 | 0.0% |
| Repubblica Democratica del Congo | 40 | 0.0% |
| Canada | 39 | 0.0% |
| El Salvador | 33 | 0.0% |
| Siria | 32 | 0.0% |
| Georgia | 31 | 0.0% |
| Mali | 31 | 0.0% |
| Australia | 30 | 0.0% |
| Belgio | 28 | 0.0% |
| Grecia | 28 | 0.0% |
| Senegal | 26 | 0.0% |
| Serbia | 25 | 0.0% |
| Turchia | 25 | 0.0% |
| Croazia | 23 | 0.0% |
| Kosovo | 23 | 0.0% |
| Corea del Sud | 23 | 0.0% |
| Gambia | 23 | 0.0% |
| Bolivia | 23 | 0.0% |
| Cile | 22 | 0.0% |
| Bielorussia | 21 | 0.0% |
| Costa d'Avorio | 19 | 0.0% |
| Honduras | 19 | 0.0% |
| Camerun | 17 | 0.0% |
| Messico | 16 | 0.0% |
| Bosnia-Erzegovina | 15 | 0.0% |
| Capo Verde | 14 | 0.0% |
| Guinea | 14 | 0.0% |
| Sudafrica | 13 | 0.0% |
| Libano | 12 | 0.0% |
| Togo | 12 | 0.0% |
| Paesi Bassi | 11 | 0.0% |
| Austria | 10 | 0.0% |
| Angola | 10 | 0.0% |
| Repubblica ceca | 9 | 0.0% |
| Giordania | 9 | 0.0% |
| Slovacchia | 8 | 0.0% |
| Israele | 8 | 0.0% |
| Thailandia | 8 | 0.0% |
| Vietnam | 8 | 0.0% |
| Armenia | 8 | 0.0% |
| Gabon | 8 | 0.0% |
| Portogallo | 7 | 0.0% |
| Kazakhstan | 7 | 0.0% |
| Paraguay | 7 | 0.0% |
| Uruguay | 7 | 0.0% |
| Ungheria | 6 | 0.0% |
| Congo | 6 | 0.0% |
| Sudan | 6 | 0.0% |
| Guatemala | 6 | 0.0% |
| Lussemburgo | 5 | 0.0% |
| Kenya | 5 | 0.0% |
| Svezia | 4 | 0.0% |
| Lettonia | 4 | 0.0% |
| Giappone | 4 | 0.0% |
| Benin | 4 | 0.0% |
| Maurizio | 4 | 0.0% |
| Mozambico | 4 | 0.0% |
| Tanzania | 4 | 0.0% |
| Nicaragua | 4 | 0.0% |
| Finlandia | 3 | 0.0% |
| Malta | 3 | 0.0% |
| Monaco | 3 | 0.0% |
| Lituania | 3 | 0.0% |
| Slovenia | 3 | 0.0% |
| Nepal | 3 | 0.0% |
| Madagascar | 3 | 0.0% |
| Sierra Leone | 3 | 0.0% |
| Panama | 3 | 0.0% |
| Irlanda | 2 | 0.0% |
| Montenegro | 2 | 0.0% |
| Oman | 2 | 0.0% |
| Azerbaigian | 2 | 0.0% |
| Liberia | 2 | 0.0% |
| Mauritania | 2 | 0.0% |
| Niger | 2 | 0.0% |
| Costa Rica | 2 | 0.0% |
| Liechtenstein | 1 | 0.0% |
| Arabia Saudita | 1 | 0.0% |
| Emirati Arabi Uniti | 1 | 0.0% |
| Palestina | 1 | 0.0% |
| Indonesia | 1 | 0.0% |
| Malaysia | 1 | 0.0% |
| Qatar | 1 | 0.0% |
| Botswana | 1 | 0.0% |
| Repubblica Centrafricana | 1 | 0.0% |
| Namibia | 1 | 0.0% |
| Seychelles | 1 | 0.0% |
| Zambia | 1 | 0.0% |
| Bahamas | 1 | 0.0% |
| Haiti | 1 | 0.0% |
Largest published groups; zero-count groups are omitted. Dimensions are source-native and are never merged. Official source14
Citizenship
Resident population in Italy at 1 January 2025; source-native country dimension; total sex · 2025-01-01
| Published group | People | Share |
|---|---|---|
| Derived source total (sum of all published country rows) | 89,011 | 100.0% |
| Italia | 77,709 | 87.3% |
| Romania | 6,285 | 7.1% |
| Egitto | 729 | 0.8% |
| Bangladesh | 374 | 0.4% |
| Cina | 293 | 0.3% |
| Albania | 259 | 0.3% |
| Perù | 258 | 0.3% |
| Marocco | 240 | 0.3% |
| Nigeria | 220 | 0.2% |
Show 113 more groups
| Published group | People | Share |
|---|---|---|
| Ucraina | 208 | 0.2% |
| Moldova | 183 | 0.2% |
| Polonia | 178 | 0.2% |
| Tunisia | 149 | 0.2% |
| Pakistan | 119 | 0.1% |
| Ghana | 100 | 0.1% |
| India | 88 | 0.1% |
| Somalia | 82 | 0.1% |
| Filippine | 67 | 0.1% |
| Algeria | 67 | 0.1% |
| Macedonia del Nord | 59 | 0.1% |
| Burkina Faso | 59 | 0.1% |
| Cuba | 57 | 0.1% |
| Brasile | 55 | 0.1% |
| Sri Lanka | 53 | 0.1% |
| Ecuador | 47 | 0.1% |
| Afghanistan | 46 | 0.1% |
| Colombia | 45 | 0.1% |
| Etiopia | 40 | 0.0% |
| Bulgaria | 38 | 0.0% |
| Iraq | 38 | 0.0% |
| Iran | 35 | 0.0% |
| Mali | 35 | 0.0% |
| Repubblica Democratica del Congo | 35 | 0.0% |
| El Salvador | 31 | 0.0% |
| Federazione russa | 29 | 0.0% |
| Georgia | 26 | 0.0% |
| Spagna | 25 | 0.0% |
| Eritrea | 25 | 0.0% |
| Corea del Sud | 24 | 0.0% |
| Siria | 24 | 0.0% |
| Gambia | 24 | 0.0% |
| Senegal | 24 | 0.0% |
| Serbia | 23 | 0.0% |
| Turchia | 22 | 0.0% |
| Germania | 21 | 0.0% |
| Croazia | 21 | 0.0% |
| Francia | 20 | 0.0% |
| Regno Unito | 19 | 0.0% |
| Repubblica Dominicana | 19 | 0.0% |
| Argentina | 19 | 0.0% |
| Venezuela | 17 | 0.0% |
| Costa d'Avorio | 16 | 0.0% |
| Camerun | 15 | 0.0% |
| Portogallo | 14 | 0.0% |
| Messico | 14 | 0.0% |
| Bolivia | 14 | 0.0% |
| Honduras | 13 | 0.0% |
| Bielorussia | 12 | 0.0% |
| Kosovo | 12 | 0.0% |
| Guinea | 12 | 0.0% |
| Capo Verde | 11 | 0.0% |
| Togo | 11 | 0.0% |
| Grecia | 10 | 0.0% |
| Congo | 10 | 0.0% |
| Dominica | 10 | 0.0% |
| Stati Uniti d'America | 10 | 0.0% |
| Bosnia-Erzegovina | 8 | 0.0% |
| Slovacchia | 8 | 0.0% |
| Armenia | 8 | 0.0% |
| Angola | 8 | 0.0% |
| Libia | 8 | 0.0% |
| Belgio | 7 | 0.0% |
| Paesi Bassi | 7 | 0.0% |
| Montenegro | 7 | 0.0% |
| San Marino | 6 | 0.0% |
| Gabon | 5 | 0.0% |
| Lettonia | 4 | 0.0% |
| Repubblica ceca | 4 | 0.0% |
| Thailandia | 4 | 0.0% |
| Benin | 4 | 0.0% |
| Tanzania | 4 | 0.0% |
| Austria | 3 | 0.0% |
| Svezia | 3 | 0.0% |
| Lituania | 3 | 0.0% |
| Giappone | 3 | 0.0% |
| Giordania | 3 | 0.0% |
| Libano | 3 | 0.0% |
| Kenya | 3 | 0.0% |
| Maurizio | 3 | 0.0% |
| Guatemala | 3 | 0.0% |
| Paraguay | 3 | 0.0% |
| Uruguay | 3 | 0.0% |
| Danimarca | 2 | 0.0% |
| Kazakhstan | 2 | 0.0% |
| Mozambico | 2 | 0.0% |
| Sudafrica | 2 | 0.0% |
| Sudan | 2 | 0.0% |
| Canada | 2 | 0.0% |
| Nicaragua | 2 | 0.0% |
| Panama | 2 | 0.0% |
| Cile | 2 | 0.0% |
| Finlandia | 1 | 0.0% |
| Lussemburgo | 1 | 0.0% |
| Svizzera | 1 | 0.0% |
| Ungheria | 1 | 0.0% |
| Slovenia | 1 | 0.0% |
| Palestina | 1 | 0.0% |
| Israele | 1 | 0.0% |
| Malaysia | 1 | 0.0% |
| Nepal | 1 | 0.0% |
| Singapore | 1 | 0.0% |
| Vietnam | 1 | 0.0% |
| Yemen | 1 | 0.0% |
| Botswana | 1 | 0.0% |
| Repubblica Centrafricana | 1 | 0.0% |
| Liberia | 1 | 0.0% |
| Madagascar | 1 | 0.0% |
| Mauritania | 1 | 0.0% |
| Niger | 1 | 0.0% |
| Haiti | 1 | 0.0% |
| Australia | 1 | 0.0% |
| Apolide | 1 | 0.0% |
Largest published groups; zero-count groups are omitted. Dimensions are source-native and are never merged. Official source13
Is Guidonia Montecelio a good place to live?
There is no universal answer. The profile scores below show who the available published evidence may suit; they are a decision aid, not a personal recommendation.
Additional context
Yes — migrants can receive medical care in Guidonia Montecelio when the national insurance or residence conditions are met.
Healthcare access follows the country-wide insurance rules; local capacity facts remain city data and are not used as proof of eligibility.
Open the official coverage guideCommon questions
Answered from the published values on this page, each with its source and date.
How many people live in Guidonia Montecelio?
The published population was 89,011 people in 2025. Source: ISTAT municipality population and citizenship tables 2025.
How much does it cost to rent in Guidonia Montecelio?
Average net cold rent is 7.5 EUR/m² per month (2025-S2), excluding heating and operating charges. For a 70 m² flat that is about 525 EUR a month before utilities. Source: Collected source.
Is the air quality good in Guidonia Montecelio?
The annual PM2.5 mean is 9 µg/m³ (2024) — above the WHO 2021 guideline of 5 µg/m³ but within the EU limit of 25 µg/m³. Source: European Environment Agency.
What is the unemployment rate in Guidonia Montecelio?
The unemployment rate is about 9.4 % (2023). Source: Eurostat.
What is the typical salary around Guidonia Montecelio?
The median gross salary is 2,189 EUR/month. Source: servizi2.inps.it.
How many foreign residents live in Guidonia Montecelio?
11,529 people residents hold a foreign nationality. Source: Official ISTAT STRASA estimate of resident foreign population by municipality at 1 January 2026; Età=999 is the total..
Is Guidonia Montecelio a good place to live?
Guidonia Montecelio may suit different people for different reasons. The page's profile scores compare published cost, work, housing, safety, healthcare and other available factors; they are a decision aid, not a universal recommendation.
How many people born in Derived source total (sum of all published country rows) live in Guidonia Montecelio?
The official country of birth distribution records 89,011 people (100.0%) in the source-defined population for 2025-01-01. This is a country of birth measure, not a general estimate of ethnicity or migration status.
Cite this page
Open a format to select or copy this ImmigrationDB compilation citation. The native disclosure and text fallback work without JavaScript.
APA citation
ImmigrationDB. (2026, September 12). Guidonia Montecelio, Italy: rent, salary [ImmigrationDB compilation; snapshot approved-static-d7ed373c115d60d0; version approved-static-d7ed373c115d60d0]. ImmigrationDB. https://immigrationdb.com/cities/it/guidonia-montecelio/ Retrieved 2026-09-12. Compilation license: CC BY 4.0, https://creativecommons.org/licenses/by/4.0/BibTeX citation
@misc{immigrationdb_immigrationdb_guidonia-montecelio-italy-rent-salary_b630b315dbdf,
author = {ImmigrationDB},
title = {Guidonia Montecelio, Italy: rent, salary},
publisher = {ImmigrationDB},
year = {2026},
date = {2026-09-12},
version = {approved-static-d7ed373c115d60d0},
snapshot = {approved-static-d7ed373c115d60d0},
url = {https://immigrationdb.com/cities/it/guidonia-montecelio/},
note = {Retrieved 2026-09-12. ImmigrationDB compilation. Compilation license: CC BY 4.0, https://creativecommons.org/licenses/by/4.0/},
}Markdown citation
[Guidonia Montecelio, Italy: rent, salary](https://immigrationdb.com/cities/it/guidonia-montecelio/) — ImmigrationDB; ImmigrationDB; snapshot approved-static-d7ed373c115d60d0; version approved-static-d7ed373c115d60d0; retrieved 2026-09-12; built 2026-09-12.This citation identifies the ImmigrationDB compilation/page. Underlying source publishers and datasets retain their own terms; inspect the Sources section and cite those records separately. View the underlying source records.
Sources
- Collected source www1.agenziaentrate.gov.it · checked 2026-08-05
- European Environment Agency air.discomap.eea.europa.eu · checked 2026-08-03
- Eurostat ec.europa.eu · checked 2026-08-02
- Eurostat ec.europa.eu · checked 2026-08-03
- Eurostat ec.europa.eu · checked 2026-08-02
- Istat (Italian National Institute of Statistics) istat.it · checked 2026-08-07
- Istat (Italian National Institute of Statistics) esploradati.istat.it · checked 2026-08-07
- Istat (Italian National Institute of Statistics) esploradati.istat.it · checked 2026-08-07
- Istat (Italian National Institute of Statistics) esploradati.istat.it · checked 2026-08-07
- Istat (Italian National Institute of Statistics) istat.it · checked 2026-08-07
Show 16 more sources
- Istat (Italian National Institute of Statistics) esploradati.istat.it · checked 2026-08-07
- ISTAT municipality population and citizenship tables 2025 demo.istat.it · checked 2026-07-26
- Istituto Nazionale di Statistica (Istat), Italy citizenship distribution demo.istat.it · checked 2026-08-28
- Istituto Nazionale di Statistica (Istat), Italy country_of_birth distribution demo.istat.it · checked 2026-08-28
- Ministero dell'Istruzione e del Merito (dati.istruzione.it) dati.istruzione.it · checked 2026-08-03
- Official ISTAT STRASA estimate of resident foreign population by municipality at 1 January 2026; Età=999 is the total. demo.istat.it · checked 2026-07-15
- Official SITUAS report 74 (Comuni - Dimensione): exact municipality surface in km2, with annual area vintage. situas-servizi.istat.it · checked 2026-07-15
- Official SITUAS report 74 (Comuni - Dimensione): exact municipality surface in km2, with annual area vintage. demo.istat.it · checked 2026-07-15
- OpenFlights raw.githubusercontent.com · checked 2026-08-03
- OurAirports davidmegginson.github.io · checked 2026-08-03
- servizi2.inps.it servizi2.inps.it · checked 2026-08-27
- World Meteorological Organization / NOAA NCEI nodc.noaa.gov · checked 2026-08-03
- World Meteorological Organization / NOAA NCEI nodc.noaa.gov · checked 2026-08-03
- World Meteorological Organization / NOAA NCEI nodc.noaa.gov · checked 2026-08-03
- World Meteorological Organization / NOAA NCEI nodc.noaa.gov · checked 2026-08-03
- World Meteorological Organization / NOAA NCEI nodc.noaa.gov · checked 2026-08-03
Spotted a number that looks wrong? Every value here carries its source and date — tell us what you found and we will re-check it against the source.