diff --git a/esphome/components/web_server/__init__.py b/esphome/components/web_server/__init__.py
index 9f7333c4eb5..9305a2de613 100644
--- a/esphome/components/web_server/__init__.py
+++ b/esphome/components/web_server/__init__.py
@@ -281,9 +281,7 @@ def add_resource_as_progmem(
     content_encoded_size = len(content_encoded)
     bytes_as_int = ", ".join(str(x) for x in content_encoded)
     uint8_t = f"constexpr uint8_t ESPHOME_WEBSERVER_{resource_name}[{content_encoded_size}] PROGMEM = {{{bytes_as_int}}}"
-    size_t = (
-        f"const size_t ESPHOME_WEBSERVER_{resource_name}_SIZE = {content_encoded_size}"
-    )
+    size_t = f"constexpr size_t ESPHOME_WEBSERVER_{resource_name}_SIZE = {content_encoded_size}"
     cg.add_global(cg.RawExpression(uint8_t))
     cg.add_global(cg.RawExpression(size_t))