diff --git a/override/uncity.go b/override/uncity.go
index 85e52b131..16b4cb358 100644
--- a/override/uncity.go
+++ b/override/uncity.go
@@ -36,6 +36,7 @@ func init() {
 	unique["services.*.expose"] = exposeIndexer
 	unique["services.*.secrets"] = mountIndexer("/run/secrets")
 	unique["services.*.configs"] = mountIndexer("")
+	unique["services.*.ports"] = portIndexer
 }
 
 // EnforceUnicity removes redefinition of elements declared in a sequence
@@ -136,3 +137,33 @@ func mountIndexer(defaultPath string) indexer {
 		}
 	}
 }
+
+func portIndexer(y any, p tree.Path) (string, error) {
+	switch value := y.(type) {
+	case map[string]any:
+		target, ok := value["target"].(int)
+		if !ok {
+			return "", fmt.Errorf("service ports %s is missing a target port", p)
+		}
+		published, ok := value["published"].(string)
+		if !ok {
+			return "", fmt.Errorf("service ports %s is missing a published port", p)
+		}
+		host, ok := value["host_ip"].(string)
+		if !ok {
+			host = "0.0.0.0"
+		}
+		protocol, ok := value["protocol"].(string)
+		if !ok {
+			protocol = "tcp"
+		}
+		mode, ok := value["mode"].(string)
+		if !ok {
+			mode = "ingress"
+		}
+		return fmt.Sprintf("%s:%s:%d/%s/%s", host, published, target, protocol, mode), nil
+	case string:
+		return value, nil
+	}
+	return "", nil
+}
diff --git a/override/uncity_test.go b/override/uncity_test.go
index 3ad46f154..189489afc 100644
--- a/override/uncity_test.go
+++ b/override/uncity_test.go
@@ -66,6 +66,74 @@ services:
 `)
 }
 
+func Test_PortsShortUnicity(t *testing.T) {
+	assertUnicity(t, `
+services:
+  test:
+    image: foo
+    ports:
+      - "9080:80"
+      - "9081:81"
+      - "9080:80"
+      - "5000"
+      - "6060:6060/udp"
+      - "9080:6060/udp"
+`, `
+services:
+  test:
+    image: foo
+    ports:
+      - "9080:80"
+      - "9081:81"
+      - "5000"
+      - "6060:6060/udp"
+      - "9080:6060/udp"
+`)
+}
+
+func Test_PortsLongtUnicity(t *testing.T) {
+	assertUnicity(t, `
+services:
+  test:
+    image: foo
+    ports:
+      - target: 80
+        host_ip: 127.0.0.1
+        published: "8080"
+        protocol: tcp
+        mode: host
+      - target: 81
+        published: "8080"
+        protocol: tcp
+      - target: 80
+        host_ip: 127.0.0.1
+        published: "8080"
+        protocol: tcp
+        mode: ingress
+      - target: 81
+        published: "8080"
+        protocol: tcp
+`, `
+services:
+  test:
+    image: foo
+    ports:
+      - target: 80
+        host_ip: 127.0.0.1
+        published: "8080"
+        protocol: tcp
+        mode: host
+      - target: 81
+        published: "8080"
+        protocol: tcp
+      - target: 80
+        host_ip: 127.0.0.1
+        published: "8080"
+        protocol: tcp
+        mode: ingress
+`)
+}
+
 func assertUnicity(t *testing.T, before string, expected string) {
 	got, err := EnforceUnicity(unmarshall(t, before))
 	assert.NilError(t, err)