diff --git a/fs-repo-12-to-13/migration/config.go b/fs-repo-12-to-13/migration/config.go
new file mode 100644
index 00000000..1233e136
--- /dev/null
+++ b/fs-repo-12-to-13/migration/config.go
@@ -0,0 +1,110 @@
+package mg12
+
+import (
+	log "github.com/ipfs/fs-repo-migrations/tools/stump"
+)
+
+// convertRouting converts Routing.Type to implicit default
+// https://github.com/ipfs/kubo/pull/9475
+func convertRouting(confMap map[string]any) {
+	routing, _ := confMap["Routing"].(map[string]any)
+	if routing == nil {
+		log.Log("No Routing field in config, skipping")
+		return
+	}
+
+	rType, ok := routing["Type"].(string)
+	if !ok {
+		log.Log("No Routing.Type field in config, skipping")
+		return
+	}
+	if rType == "dht" || rType == "" {
+		delete(routing, "Type")
+	} else {
+		log.Log("Routing.Type settings is different than the old default, skipping")
+	}
+}
+
+// convertReprovider converts Reprovider to implicit defaults
+// https://github.com/ipfs/kubo/pull/9326
+func convertReprovider(confMap map[string]any) {
+	reprovider, _ := confMap["Reprovider"].(map[string]any)
+	if reprovider == nil {
+		log.Log("No Reprovider field in config, skipping")
+		return
+	}
+
+	interval, ok := reprovider["Interval"].(string)
+	if !ok {
+		log.Log("No Reprovider.Interval field in config, skipping")
+		return
+	}
+	if interval == "12h" {
+		delete(reprovider, "Interval")
+	} else {
+		log.Log("Reprovider.Interval settings is different than the old default, skipping")
+	}
+
+	strategy, ok := reprovider["Strategy"].(string)
+	if !ok {
+		log.Log("No Reprovider.Strategy field in config, skipping")
+		return
+	}
+	if strategy == "all" {
+		delete(reprovider, "Strategy")
+	} else {
+		log.Log("Reprovider.Strategy settings is different than the old default, skipping")
+	}
+}
+
+// convertConnMgr converts Swarm.ConnMgr to implicit defaults
+// https://github.com/ipfs/kubo/pull/9467
+func convertConnMgr(confMap map[string]any) {
+	swarm, _ := confMap["Swarm"].(map[string]any)
+	if swarm == nil {
+		log.Log("No Swarm field in config, skipping")
+		return
+	}
+	connmgr, _ := swarm["ConnMgr"].(map[string]any)
+	if connmgr == nil {
+		log.Log("No Swarm.ConnMgr field in config, skipping")
+		return
+	}
+	cmType, ok := connmgr["Type"].(string)
+	if !ok {
+		log.Log("No Swarm.ConnMgr.Type field in config, skipping")
+		return
+	}
+	cmLowWater, ok := connmgr["LowWater"].(float64)
+	if !ok {
+		log.Log("No Swarm.ConnMgr.LowWater field in config, skipping")
+		return
+	}
+	cmHighWater, ok := connmgr["HighWater"].(float64)
+	if !ok {
+		log.Log("No Swarm.ConnMgr.HighWater field in config, skipping")
+		return
+	}
+	cmGrace, ok := connmgr["GracePeriod"].(string)
+	if !ok {
+		log.Log("No Swarm.ConnMgr.GracePeriod field in config, skipping")
+		return
+	}
+
+	if cmType == "basic" {
+		delete(connmgr, "Type")
+		if cmGrace == "20s" {
+			delete(connmgr, "GracePeriod")
+		} else {
+			log.Log("Swarm.ConnMgr.GracePeriod setting are different than the old defaults, skipping")
+		}
+		if int(cmLowWater) == 600 && int(cmHighWater) == 900 {
+			delete(connmgr, "LowWater")
+			delete(connmgr, "HighWater")
+		} else {
+			log.Log("Swarm.ConnMgr Low/HighWater settings are different than the old defaults, skipping")
+		}
+	} else {
+		log.Log("Swarm.ConnMgr settings are different than the old defaults, skipping")
+	}
+}
diff --git a/fs-repo-12-to-13/migration/config_test.go b/fs-repo-12-to-13/migration/config_test.go
new file mode 100644
index 00000000..3d63253e
--- /dev/null
+++ b/fs-repo-12-to-13/migration/config_test.go
@@ -0,0 +1,84 @@
+package mg12
+
+import (
+	"bytes"
+	"encoding/json"
+	"io/ioutil"
+	"regexp"
+	"strings"
+	"testing"
+)
+
+var beforeConfig = `{
+  "Reprovider": {
+    "Interval": "12h",
+	"Strategy": "all"
+  },
+  "Routing": {
+	"Methods": {},
+	"Routers": {},
+    "Type": "dht"
+  },
+  "Swarm": {
+	"ConnMgr": {
+		"GracePeriod": "20s",
+		"HighWater": 900,
+		"LowWater": 600,
+		"Type": "basic"
+	}
+  }
+}`
+
+var afterConfig = `{
+  "Reprovider": {},
+  "Routing": {
+	"Methods": {},
+	"Routers": {}
+  },
+  "Swarm": {
+    "ConnMgr": {}
+  }
+}`
+
+func TestKubo18ConfigMigration(t *testing.T) {
+	out := new(bytes.Buffer)
+
+	data, err := ioutil.ReadAll(strings.NewReader(beforeConfig))
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	confMap := make(map[string]interface{})
+	if err = json.Unmarshal(data, &confMap); err != nil {
+		t.Fatal(err)
+	}
+
+	// Kubo 0.18
+	convertRouting(confMap)
+	convertReprovider(confMap)
+	convertConnMgr(confMap)
+
+	fixed, err := json.MarshalIndent(confMap, "", "  ")
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	if _, err := out.Write(fixed); err != nil {
+		t.Fatal(err)
+	}
+	_, err = out.Write([]byte("\n"))
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	forward := out.String()
+	if noSpace(forward) != noSpace(afterConfig) {
+		t.Fatalf("Mismatch\nConversion produced:\n%s\nExpected:\n%s\n", forward, afterConfig)
+	}
+}
+
+var whitespaceRe = regexp.MustCompile(`\s`)
+
+func noSpace(str string) string {
+	return whitespaceRe.ReplaceAllString(str, "")
+}
diff --git a/fs-repo-12-to-13/migration/migration.go b/fs-repo-12-to-13/migration/migration.go
index 95e24a91..99da4dd3 100644
--- a/fs-repo-12-to-13/migration/migration.go
+++ b/fs-repo-12-to-13/migration/migration.go
@@ -1,5 +1,6 @@
 // package mg12 contains the code to perform 12-13 repository migration in Kubo.
-// This just change some config fields to add webtransport listens on ones that quic uses.
+// This just change some config fields to add webtransport listens on ones that quic uses,
+// and removes some hardcoded defaults that are no longer present on fresh 'ipfs init'.
 package mg12
 
 import (
@@ -27,7 +28,7 @@ func (m Migration) Versions() string {
 	return "12-to-13"
 }
 
-// Reversible returns false, as you can just use the backup config file.
+// Reversible returns true, as we keep old config around
 func (m Migration) Reversible() bool {
 	return true
 }
@@ -156,6 +157,10 @@ func convert(in io.Reader, out io.Writer) error {
 	runOnAllAddressFields(confMap, multiaddrPatternReplace(true, "/quic", "/quic-v1", "/p2p-circuit"))
 	runOnAllAddressFields(confMap, multiaddrPatternReplace(true, "/quic-v1", "/quic-v1/webtransport", "/p2p-circuit", "/webtransport"))
 
+	convertRouting(confMap)
+	convertReprovider(confMap)
+	convertConnMgr(confMap)
+
 	fixed, err := json.MarshalIndent(confMap, "", "  ")
 	if err != nil {
 		return err