diff --git a/maputil/maputil.go b/maputil/maputil.go
index 4e047c289..96247fd92 100644
--- a/maputil/maputil.go
+++ b/maputil/maputil.go
@@ -22,12 +22,19 @@ func SimpleMerge(src, dst map[string]any) map[string]any {
 	if len(src) == 0 {
 		return dst
 	}
-
 	if len(dst) == 0 {
 		return src
 	}
 
 	for key, val := range src {
+		if mp, ok := val.(map[string]any); ok {
+			if dmp, ok := dst[key].(map[string]any); ok {
+				dst[key] = SimpleMerge(mp, dmp)
+				continue
+			}
+		}
+
+		// simple merge
 		dst[key] = val
 	}
 	return dst
@@ -54,7 +61,6 @@ func MergeStringMap(src, dst map[string]string, ignoreCase bool) map[string]stri
 		if ignoreCase {
 			k = strings.ToLower(k)
 		}
-
 		dst[k] = v
 	}
 	return dst
diff --git a/maputil/maputil_test.go b/maputil/maputil_test.go
index 6dcbff825..7e220f5a8 100644
--- a/maputil/maputil_test.go
+++ b/maputil/maputil_test.go
@@ -22,6 +22,19 @@ func TestSimpleMerge(t *testing.T) {
 
 	ret = maputil.SimpleMerge(src, nil)
 	assert.Eq(t, "v0", ret["A"])
+
+	src = map[string]any{"A": "v0", "B": "v1", "sub": map[string]any{"s1": "sv0"}}
+	dst = map[string]any{"A": "v1", "B": "v2", "sub": map[string]any{
+		"s1": "sv1",
+		"s2": "sv2",
+	}}
+	ret = maputil.SimpleMerge(src, dst)
+
+	dm := maputil.Data(ret)
+	assert.Eq(t, "v0", dm.Str("A"))
+	assert.Eq(t, "v1", dm.Str("B"))
+	assert.Eq(t, "sv0", dm.Str("sub.s1"))
+	assert.Eq(t, "sv2", dm.Str("sub.s2"))
 }
 
 func TestMergeStringMap(t *testing.T) {
@@ -30,6 +43,12 @@ func TestMergeStringMap(t *testing.T) {
 
 	ret = maputil.MergeSMap(map[string]string{"A": "v0"}, map[string]string{"a": "v1"}, true)
 	assert.Eq(t, map[string]string{"a": "v0"}, ret)
+
+	ret = maputil.MergeSMap(map[string]string{"A": "v0"}, nil, false)
+	assert.Eq(t, map[string]string{"A": "v0"}, ret)
+
+	ret = maputil.MergeSMap(nil, map[string]string{"a": "v1"}, true)
+	assert.Eq(t, map[string]string{"a": "v1"}, ret)
 }
 
 func TestMakeByPath(t *testing.T) {