diff --git a/keyserver/.flowconfig b/keyserver/.flowconfig
--- a/keyserver/.flowconfig
+++ b/keyserver/.flowconfig
@@ -33,6 +33,7 @@
 deprecated-type=warn
 unsafe-getters-setters=warn
 unnecessary-invariant=warn
+unused-promise=error
 
 [strict]
 deprecated-type
diff --git a/landing/.flowconfig b/landing/.flowconfig
--- a/landing/.flowconfig
+++ b/landing/.flowconfig
@@ -21,6 +21,7 @@
 deprecated-type=warn
 unsafe-getters-setters=warn
 unnecessary-invariant=warn
+unused-promise=error
 
 [strict]
 deprecated-type
diff --git a/lib/.flowconfig b/lib/.flowconfig
--- a/lib/.flowconfig
+++ b/lib/.flowconfig
@@ -20,6 +20,7 @@
 deprecated-type=warn
 unsafe-getters-setters=warn
 unnecessary-invariant=warn
+unused-promise=error
 
 [strict]
 deprecated-type
diff --git a/native/.flowconfig b/native/.flowconfig
--- a/native/.flowconfig
+++ b/native/.flowconfig
@@ -63,6 +63,7 @@
 deprecated-type=warn
 unsafe-getters-setters=warn
 unnecessary-invariant=warn
+unused-promise=error
 
 [strict]
 deprecated-type
diff --git a/services/electron-update-server/.flowconfig b/services/electron-update-server/.flowconfig
--- a/services/electron-update-server/.flowconfig
+++ b/services/electron-update-server/.flowconfig
@@ -12,6 +12,7 @@
 deprecated-type=warn
 unsafe-getters-setters=warn
 unnecessary-invariant=warn
+unused-promise=error
 
 [strict]
 deprecated-type
diff --git a/web/.flowconfig b/web/.flowconfig
--- a/web/.flowconfig
+++ b/web/.flowconfig
@@ -24,6 +24,7 @@
 deprecated-type=warn
 unsafe-getters-setters=warn
 unnecessary-invariant=warn
+unused-promise=error
 
 [strict]
 deprecated-type