diff --git a/kong/plugins/basicauth2keyauth/handler.lua b/kong/plugins/basicauth2keyauth/handler.lua
index 71a1a76..3f0d855 100644
--- a/kong/plugins/basicauth2keyauth/handler.lua
+++ b/kong/plugins/basicauth2keyauth/handler.lua
@@ -13,7 +13,7 @@ local function retrieve_credentials(request, header_name, conf)
   local authorization_header = request.get_headers()[header_name]
 
   if authorization_header then
-    local iterator, iter_err = ngx.re.gmatch(authorization_header, "\\s*[Bb]asic\\s*(.+)")
+    local iterator, iter_err = ngx.re.gmatch(authorization_header, "\\s*Basic\\s*(.+)", "oji")
     if not iterator then
       ngx.log(ngx.ERR, iter_err)
       return
diff --git a/spec/basicauth2keyauth/01-access_spec.lua b/spec/basicauth2keyauth/01-access_spec.lua
index 16f4ca9..03e0b2d 100644
--- a/spec/basicauth2keyauth/01-access_spec.lua
+++ b/spec/basicauth2keyauth/01-access_spec.lua
@@ -100,5 +100,18 @@ describe("Plugin: key-auth (access)", function()
       local header_value = assert.request(res).has.header("apikey_from_basicauth")
       assert.equal("632d187cde1f395f3fb17e9783748d101b70174988a8e148bc7bc20f63453ea5", header_value)
     end)
+    it("generates new api_key header with sha256 value if basic is in upper case", function()
+      local res = assert(client:send {
+        method = "GET",
+        path = "/request",
+        headers = {
+          ["Host"] = "host2.com",
+          ["Authorization"] = "BASIC YXBpMTIzNA==" -- "api1234"
+        }
+      })
+      assert.res_status(200, res)
+      local header_value = assert.request(res).has.header("apikey_from_basicauth")
+      assert.equal("632d187cde1f395f3fb17e9783748d101b70174988a8e148bc7bc20f63453ea5", header_value)
+    end)
   end)
 end)