diff --git a/internal/catalogue/bound_into_files_test.go b/internal/catalogue/bound_into_files_test.go
index 278cc6c..011a1ce 100644
--- a/internal/catalogue/bound_into_files_test.go
+++ b/internal/catalogue/bound_into_files_test.go
@@ -1,6 +1,7 @@
 package catalogue
 
 import (
+	"fmt"
 	"strings"
 	"testing"
 )
@@ -53,6 +54,69 @@ func TestAConsumerCanWriteAConnectionString(t *testing.T) {
 	}
 }
 
+// A provider answered on its consumer's own machine is announced at the port the machine PUBLISHES
+// it on, not the port the module declared (novox/hq 04-ISSUES/038).
+//
+// Issue 018 made the same-node provider announced at all; this is the promise after it — that the
+// port a co-located consumer is told is the one actually listening at the address it is handed. The
+// mesh assigns a bare `ports` mapping a host port (here the container's 5432 becomes 15432 on this
+// machine), and it must announce 15432, or the consumer dials workstation.internal:5432 where the
+// provider is not published. Cross-node consumers already got this (the plan re-derives the served
+// facts with the provider's assignment); the same-node need was settled before the assignment and
+// carried the declared port until now.
+func TestASameNodeProviderIsAnnouncedAtThePortItIsPublishedOn(t *testing.T) {
+	provider := Manifest{
+		Module: "postgres", Version: "1",
+		Provides: FromAnywhere("postgres-database"),
+		Listens:  []Listening{{Port: 5432, Protocol: "tcp", From: "mesh"}},
+		Serves:   map[string]map[string]any{"postgres-database": {"port": 5432}},
+		Resources: []map[string]any{{
+			"id": "server", "type": "container", "name": "postgres",
+			"ports": []any{"5432"},
+		}},
+	}
+	consumer := Manifest{
+		Module: "keycloak", Version: "1", Requires: []string{"postgres-database"},
+		Resources: []map[string]any{{
+			"id": "dbenv", "type": "file", "path": "/var/lib/keycloak/database.env", "mode": "0600",
+			"content": "KC_DB_URL=jdbc:postgresql://${bound:postgres-database:at}:" +
+				"${bound:postgres-database:port}/keycloak\n",
+		}},
+	}
+	r, err := Resolve(shelf(provider, consumer),
+		[]string{"postgres", "keycloak"}, reachable(), World{})
+	if err != nil {
+		t.Fatal(err)
+	}
+	// The mesh assigned the container's 5432 to 15432 on this machine.
+	out, err := r.Declaration(Rendering{Ports: map[string]map[int]int{"postgres": {5432: 15432}}})
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	// Where the provider is actually published: the assigned host port, on the machine at large.
+	server := fileNamed(out, "postgres.server")
+	if server == nil {
+		t.Fatalf("the provider container is not in the declaration: %v", out)
+	}
+	if published := fmt.Sprint(server["ports"]); !strings.Contains(published, "15432:5432") {
+		t.Fatalf("the provider was not published on the assigned port: %v", server["ports"])
+	}
+
+	// What the consumer was told to dial: the SAME port, at the announced address — not the 5432 the
+	// module declared, which is closed on that address.
+	dbenv := fileNamed(out, "keycloak.dbenv")
+	if dbenv == nil {
+		t.Fatalf("the consumer's binding file is not in the declaration: %v", out)
+	}
+	got := dbenv["content"].(string)
+	want := "KC_DB_URL=jdbc:postgresql://workstation.internal:15432/keycloak\n"
+	if got != want {
+		t.Errorf("the consumer dials a port the provider does not listen on:\n got %q\nwant %q",
+			got, want)
+	}
+}
+
 // A port is 5432, not 5432.000000 — which is what a number decoded from JSON would write, and what
 // every connection string in the world would refuse.
 func TestAPortIsWrittenAsAPort(t *testing.T) {
diff --git a/internal/catalogue/declaration.go b/internal/catalogue/declaration.go
index 470c8ba..bbebd42 100644
--- a/internal/catalogue/declaration.go
+++ b/internal/catalogue/declaration.go
@@ -141,6 +141,21 @@ func (r Resolution) Declaration(with Rendering) ([]map[string]any, error) {
 		return nil, err
 	}
 
+	// A provider answered on this same machine is announced at the port it *declared*, because the
+	// need was settled while resolving — before this machine assigned the port a bare `ports`
+	// mapping is published on (novox/hq 04-ISSUES/038). Redirect those same-node needs to where the
+	// machine actually publishes the provider, exactly as the cross-node path already does with the
+	// provider's own assignment, so a co-located consumer is told the port that is really listening.
+	servedBy := servedByModule(r.Modules)
+	for i := range r.Needs {
+		if r.Needs[i].From != r.Node {
+			continue
+		}
+		if module, ok := servedBy[r.Needs[i].Name]; ok {
+			r.Needs[i].Serves = atMachinePort(r.Needs[i].Serves, module, with.Ports)
+		}
+	}
+
 	// Once, from every module's listens -- not per module. A module receiving only its own ports
 	// would write a rule set that closed every other module on the machine. Each module's per-node
 	// exposure settings override its listens' source first (novox/hq ADR 0046).
@@ -311,6 +326,11 @@ func (r Resolution) Declaration(with Rendering) ([]map[string]any, error) {
 					// requirement met by the module itself.
 					continue
 				}
+				// Answered here, so its served port needs the same redirect the resolver's
+				// same-node needs got above — this fallback builds one afresh, outside r.Needs.
+				if provider, ok := servedBy[to]; ok {
+					here.Serves = atMachinePort(here.Serves, provider, with.Ports)
+				}
 				found = here
 			}
 			file, err := boundFile(*found, m.Binds[to], ConsumerIdentity(r.Node, IdentitySource(m.Slug, m.Module)))
@@ -838,3 +858,49 @@ func asPort(v any) (int, bool) {
 	}
 	return 0, false
 }
+
+// servedByModule maps each provision offered on this node to the module that offers it.
+//
+// The same node may both provide and consume a provision, and a consumer's binding names the
+// provision, not the module behind it — so redirecting a served port to where the machine put it
+// needs this reverse lookup, from the provision back to the module whose assignment moved it.
+func servedByModule(mods []Manifest) map[string]string {
+	out := map[string]string{}
+	for _, m := range mods {
+		for provision := range m.Serves {
+			out[provision] = m.Module
+		}
+	}
+	return out
+}
+
+// atMachinePort redirects a served `port` fact to where this machine actually published the
+// provider (novox/hq 04-ISSUES/038).
+//
+// **Same-node served facts are settled before the machine's port is assigned.** The resolver names
+// what a consumer must know (resolve.go's servedHere, declaration.go's here()) while resolving,
+// which happens before a bare `ports` declaration is assigned a host port — so it can only carry
+// the port the provider *declared*. The cross-node path re-derives the fact after assignment, with
+// the provider node's port map (cmd plan.go), and so already tells the truth. This closes the gap
+// for the co-located case: without it a consumer is announced `<node>.internal:<declared>` while
+// the provider is published on `<node>.internal:<assigned>`, and dials a port nothing listens on.
+//
+// A fresh map when it changes anything, so the manifest-derived value the resolver handed back is
+// never mutated under a caller that still holds it. Keyed by the *declared* port, so applying it a
+// second time is a no-op: once redirected the value is the machine port, which is not itself a key.
+func atMachinePort(serves map[string]any, module string, ports map[string]map[int]int) map[string]any {
+	number, ok := asPort(serves["port"])
+	if !ok {
+		return serves
+	}
+	at, known := ports[module][number]
+	if !known || at == number {
+		return serves
+	}
+	copied := make(map[string]any, len(serves))
+	for k, v := range serves {
+		copied[k] = v
+	}
+	copied["port"] = at
+	return copied
+}