diff --git a/.flowconfig b/.flowconfig
index f99611e83eb..3e6add1dbc8 100644
--- a/.flowconfig
+++ b/.flowconfig
@@ -73,6 +73,7 @@ unsafe-getters-setters=warn
 unnecessary-invariant=warn
 signature-verification-failure=warn
 deprecated-utility=error
+unsafe-addition=error
 
 [strict]
 deprecated-type
diff --git a/.flowconfig.android b/.flowconfig.android
index 1b4039c6824..b3ecb7e9ac1 100644
--- a/.flowconfig.android
+++ b/.flowconfig.android
@@ -73,6 +73,7 @@ unsafe-getters-setters=warn
 unnecessary-invariant=warn
 signature-verification-failure=warn
 deprecated-utility=error
+unsafe-addition=error
 
 [strict]
 deprecated-type