diff --git a/config/allconfig/allconfig_integration_test.go b/config/allconfig/allconfig_integration_test.go
index debdff650..1b677884f 100644
--- a/config/allconfig/allconfig_integration_test.go
+++ b/config/allconfig/allconfig_integration_test.go
@@ -160,3 +160,21 @@ title: "p3"
 	b.AssertFileExists("public/page/1/index.html", false)
 	b.AssertFileContent("public/page/2/index.html", "pagination-default")
 }
+
+
+func TestMapUglyURLs(t *testing.T) {
+	files := `
+-- hugo.toml --
+[uglyurls]
+  posts = true
+`
+
+	b := hugolib.Test(t, files)
+
+	c := b.H.Configs.Base
+
+	mapUglyURLs, isMap := c.UglyURLs.(map[string]bool)
+
+	b.Assert(isMap, qt.Equals, true)
+	b.Assert(mapUglyURLs["posts"], qt.Equals, true)
+}
diff --git a/config/allconfig/alldecoders.go b/config/allconfig/alldecoders.go
index 45cdd0de6..60e571999 100644
--- a/config/allconfig/alldecoders.go
+++ b/config/allconfig/alldecoders.go
@@ -419,6 +419,8 @@ var allDecoderSetups = map[string]decodeWeight{
 				p.c.UglyURLs = vv
 			case string:
 				p.c.UglyURLs = vv == "true"
+			case maps.Params:
+				p.c.UglyURLs = cast.ToStringMapBool(maps.CleanConfigStringMap(vv))
 			default:
 				p.c.UglyURLs = cast.ToStringMapBool(v)
 			}