diff --git a/bitcask.go b/bitcask.go
index 1bf4050..af2a472 100644
--- a/bitcask.go
+++ b/bitcask.go
@@ -446,7 +446,7 @@ func (b *Bitcask) Merge() error {
 	defer os.RemoveAll(temp)
 
 	// Create a merged database
-	mdb, err := Open(temp, b.options...)
+	mdb, err := Open(temp, withConfig(b.config))
 	if err != nil {
 		return err
 	}
diff --git a/go.mod b/go.mod
index 87d4ff4..890ec3c 100644
--- a/go.mod
+++ b/go.mod
@@ -19,5 +19,5 @@ require (
 	golang.org/x/exp v0.0.0-20200228211341-fcea875c7e85
 	golang.org/x/sys v0.0.0-20200302150141-5c8b2ff67527
 	gopkg.in/ini.v1 v1.53.0 // indirect
-	gopkg.in/yaml.v2 v2.2.8 // indirect
+	gopkg.in/yaml.v2 v2.3.0 // indirect
 )
diff --git a/go.sum b/go.sum
index 6df9484..8a9f85f 100644
--- a/go.sum
+++ b/go.sum
@@ -275,7 +275,6 @@ golang.org/x/sys v0.0.0-20181116152217-5ac8a444bdc5/go.mod h1:STP8DvDyc/dI5b8T5h
 golang.org/x/sys v0.0.0-20190215142949-d0b11bdaac8a/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
 golang.org/x/sys v0.0.0-20190312061237-fead79001313/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20190412213103-97732733099d/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
-golang.org/x/sys v0.0.0-20190422165155-953cdadca894/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20190502145724-3ef323f4f1fd/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20190507160741-ecd444e8653b/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20190606165138-5da285871e9c/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
@@ -345,8 +344,8 @@ gopkg.in/yaml.v2 v2.0.0-20170812160011-eb3733d160e7/go.mod h1:JAlM8MvJe8wmxCU4Bl
 gopkg.in/yaml.v2 v2.2.1/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=
 gopkg.in/yaml.v2 v2.2.2/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=
 gopkg.in/yaml.v2 v2.2.4/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=
-gopkg.in/yaml.v2 v2.2.8 h1:obN1ZagJSUGI0Ek/LBmuj4SNLPfIny3KsKFopxRdj10=
-gopkg.in/yaml.v2 v2.2.8/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=
+gopkg.in/yaml.v2 v2.3.0 h1:clyUAQHOM3G0M3f5vQj7LuJrETvjVot3Z5el9nffUtU=
+gopkg.in/yaml.v2 v2.3.0/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=
 gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c h1:dUUwHk2QECo/6vqA44rthZ8ie2QXMNeKRTHCNY2nXvo=
 gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=
 honnef.co/go/tools v0.0.0-20190102054323-c2f93a96b099/go.mod h1:rf3lG4BRIbNafJWhAfAdb/ePZxsR/4RtNHQocxwk9r4=
diff --git a/internal/index/codec_index.go b/internal/index/codec_index.go
index 6d0ff7f..3f1d006 100644
--- a/internal/index/codec_index.go
+++ b/internal/index/codec_index.go
@@ -34,7 +34,7 @@ func readKeyBytes(r io.Reader, maxKeySize uint32) ([]byte, error) {
 		return nil, errors.Wrap(errTruncatedKeySize, err.Error())
 	}
 	size := binary.BigEndian.Uint32(s)
-	if size > uint32(maxKeySize) {
+	if maxKeySize > 0 && size > uint32(maxKeySize) {
 		return nil, errKeySizeTooLarge
 	}
 
diff --git a/options.go b/options.go
index c92e5a4..86d8ee3 100644
--- a/options.go
+++ b/options.go
@@ -31,6 +31,19 @@ const (
 // Option is a function that takes a config struct and modifies it
 type Option func(*config.Config) error
 
+func withConfig(src *config.Config) Option {
+	return func(cfg *config.Config) error {
+		cfg.MaxDatafileSize = src.MaxDatafileSize
+		cfg.MaxKeySize = src.MaxKeySize
+		cfg.MaxValueSize = src.MaxValueSize
+		cfg.Sync = src.Sync
+		cfg.AutoRecovery = src.AutoRecovery
+		cfg.DirFileModeBeforeUmask = src.DirFileModeBeforeUmask
+		cfg.FileFileModeBeforeUmask = src.FileFileModeBeforeUmask
+		return nil
+	}
+}
+
 // WithAutoRecovery sets auto recovery of data and index file recreation.
 // IMPORTANT: This flag MUST BE used only if a proper backup was made of all
 // the existing datafiles.