diff --git a/types/suncalc/tsconfig.json b/types/suncalc/tsconfig.json
index ce875cd1d7..0225e8390e 100644
--- a/types/suncalc/tsconfig.json
+++ b/types/suncalc/tsconfig.json
@@ -6,7 +6,9 @@
         ],
         "noImplicitAny": true,
         "noImplicitThis": true,
+        "strict": true,
         "strictNullChecks": true,
+        "strictFunctionTypes": true,
         "baseUrl": "../",
         "typeRoots": [
             "../"