diff --git a/esphome/components/sha256/__init__.py b/esphome/components/sha256/__init__.py
index f07157416..5db0e77b7 100644
--- a/esphome/components/sha256/__init__.py
+++ b/esphome/components/sha256/__init__.py
@@ -12,6 +12,8 @@ CONFIG_SCHEMA = cv.Schema({})
 
 
 async def to_code(config: ConfigType) -> None:
+    cg.add_define("USE_SHA256")
+
     # Add OpenSSL library for host platform
     if not CORE.is_host:
         return