diff --git a/demo/examples/openapi-cos.json b/demo/examples/openapi-cos.json
index ce5a01fb..c784b3a1 100644
--- a/demo/examples/openapi-cos.json
+++ b/demo/examples/openapi-cos.json
@@ -138,7 +138,7 @@
   },
   "components": {
     "securitySchemes": {
-      "BearerAuth": { "type": "http", "scheme": "bearer" },
+      "BearerAuth": { "type": "http", "scheme": "BeAreR" },
       "BasicAuth": { "type": "http", "scheme": "basic" }
     },
     "schemas": {
diff --git a/packages/docusaurus-plugin-openapi/src/openapi.ts b/packages/docusaurus-plugin-openapi/src/openapi.ts
index a15d9b87..6462e787 100644
--- a/packages/docusaurus-plugin-openapi/src/openapi.ts
+++ b/packages/docusaurus-plugin-openapi/src/openapi.ts
@@ -25,8 +25,23 @@ import {
   ApiItem,
   RequestBodyObject,
   SchemaObject,
+  HttpSecuritySchemeObject,
+  ApiKeySecuritySchemeObject,
+  Oauth2SecuritySchemeObject,
+  OpenIdConnectSecuritySchemeObject,
 } from "./types";
 
+function isHttpSecuritySchemeObject(
+  item:
+    | ReferenceObject
+    | ApiKeySecuritySchemeObject
+    | HttpSecuritySchemeObject
+    | Oauth2SecuritySchemeObject
+    | OpenIdConnectSecuritySchemeObject
+): item is HttpSecuritySchemeObject {
+  return (item as HttpSecuritySchemeObject).type === "http";
+}
+
 function isOperationObject(
   item:
     | string
@@ -234,6 +249,13 @@ export async function loadOpenapi(
       // Add security schemes so we know how to handle security.
       item.securitySchemes = dereffedSpec.components?.securitySchemes;
 
+      // Make sure schemes are lowercase. See: https://github.com/cloud-annotations/docusaurus-plugin-openapi/issues/79
+      Object.values(item.securitySchemes ?? {}).forEach((auth) => {
+        if (isHttpSecuritySchemeObject(auth)) {
+          auth.scheme = auth.scheme.toLowerCase();
+        }
+      });
+
       item.permalink = normalizeUrl([baseUrl, routeBasePath, item.id]);
 
       const prev =