diff --git a/solution_architecture.md b/solution_architecture.md
index 1e306f8..e5a742c 100644
--- a/solution_architecture.md
+++ b/solution_architecture.md
@@ -272,7 +272,7 @@ If the back end calls from the mobile applications cannot be spread as evenly as
 A definite prerequisite for compatibility is that the identifiers of the mobile devices can be matched, i.e. the GAEN framework by Apple and Google is being used.
 
 [Most European countries are developing similar contact tracing apps](https://ec.europa.eu/info/live-work-travel-eu/health/coronavirus-response/travel-during-coronavirus-pandemic/mobile-contact-tracing-apps-eu-member-states_en). These apps may use the common frameworks by Google and Apple, enabling transmission and detection of GAEN format diagnosis keys between devices running different contact tracing applications. 
-Each country has its own separate database which contains the keys from infected individuals. In order to coordinate exposure information between countries, a common service is required to enable interoperability.
+Each country has its own separate database, which contains the keys from infected individuals. In order to coordinate exposure information between countries, a common service is required to enable interoperability.
 The [European Federation Gateway Service (EFGS)](https://github.com/eu-federation-gateway-service/efgs-federation-gateway) enables interoperability of diagnosis keys between the connected country backend servers.
 
 ![Figure 15: High-level EFGS overview](images/solution_architecture/EFGS_overview.jpg "Figure 15: High-level EFGS overview")