diff --git a/lib/jsonschema.lua b/lib/jsonschema.lua
index dc1f7ed..aed9c95 100644
--- a/lib/jsonschema.lua
+++ b/lib/jsonschema.lua
@@ -943,7 +943,7 @@ generate_validator = function(ctx, schema)
     end
     if schema.pattern then
       ctx:stmt(sformat('  if not %s(%s, %q) then', ctx:libfunc('custom.match_pattern'), ctx:param(1), schema.pattern))
-      ctx:stmt(sformat('    return false, %s([[failed to match pattern %q with %%q]], %s)', ctx:libfunc('string.format'), schema.pattern, ctx:param(1)))
+      ctx:stmt(sformat('    return false, %s([[failed to match pattern %q with %%q]], %s)', ctx:libfunc('string.format'), string.gsub(schema.pattern, "%%", "%%%%"), ctx:param(1)))
       ctx:stmt(        '  end')
     end
     ctx:stmt('end') -- if string
diff --git a/t/default.lua b/t/default.lua
index dedfce2..4a3508e 100644
--- a/t/default.lua
+++ b/t/default.lua
@@ -213,3 +213,23 @@ for i, case in ipairs(cases) do
     assert(ok, string.format("fail: validate case %d,  err: %s, ", i, err))
 end
 ngx.say("passed: check string len")
+
+----------------------------------------------------- test case 8
+-- test pattern with `%`
+local host_pattern = [[^http(s)?:\/\/[a-zA-Z0-9-_.:\@%]+$]]
+local rule = {
+    type = "object",
+    properties = {
+        foo = {
+            pattern = host_pattern,
+        },
+    },
+}
+
+local validator = jsonschema.generate_validator(rule)
+local t = {
+    foo = "http://#baidu.com"
+}
+local ok, err = validator(t)
+assert(ok~=nil, ("pattern: failed to check pattern with `%%`: %s"):format(err))
+ngx.say("passed: pass check pattern with `%`")