diff --git a/internal/agent/inventory/collector.go b/internal/agent/inventory/collector.go
index 120c411..832599a 100644
--- a/internal/agent/inventory/collector.go
+++ b/internal/agent/inventory/collector.go
@@ -279,7 +279,18 @@ func (c *Collector) markBuilt(ctx context.Context, byKey map[string]protocol.Ser
 		if svc.Kind != protocol.KindCompose {
 			continue
 		}
-		if c.builtServices(ctx, svc.ComposeProject, stacks[svc.ComposeProject])[svc.ComposeService] {
+		built := c.builtServices(ctx, svc.ComposeProject, stacks[svc.ComposeProject])
+		if built == nil {
+			continue // check failed; already logged
+		}
+		isBuilt, known := built[svc.ComposeService]
+		if !known {
+			// Fail closed: a service compose does not list cannot be shown to
+			// be free of build:, so it is not offered for update.
+			c.warnOnce(svc.ComposeProject+"/"+svc.ComposeService, "compose_service_not_in_config",
+				"project", svc.ComposeProject, "service", svc.ComposeService)
+		}
+		if isBuilt || !known {
 			svc.Built = true
 			byKey[key] = svc
 		}
@@ -289,6 +300,10 @@ func (c *Collector) markBuilt(ctx context.Context, byKey map[string]protocol.Ser
 // builtServices returns the project's built services, from the cache while
 // the project's files are unchanged.
 func (c *Collector) builtServices(ctx context.Context, project string, l stackLabels) map[string]bool {
+	// The key covers the files named in the labels. Changes in files they
+	// pull in (extends:, include:, the default .env) do not invalidate the
+	// cache, so Built can be stale until another change or an agent restart.
+	// The job-time check is always fresh, so jobs stay safe.
 	key := l.workingDir + "|" + l.configFiles + "|" + l.envFile + "|" + fileStamps(l.configFiles+","+l.envFile)
 	c.mu.Lock()
 	defer c.mu.Unlock()
@@ -297,18 +312,30 @@ func (c *Collector) builtServices(ctx context.Context, project string, l stackLa
 	}
 	built, err := c.check.BuiltServices(ctx, project, l.workingDir, l.configFiles, l.envFile)
 	c.cache[project] = buildEntry{key: key, built: built, err: err, at: c.now()}
-	switch {
-	case err == nil:
+	if err == nil {
 		delete(c.warned, project)
-	case !c.warned[project]:
-		c.warned[project] = true
-		if c.log != nil {
-			c.log.Warn("compose_build_check_failed", "project", project, "error", err)
-		}
+	} else {
+		c.warnOnceLocked(project, "compose_build_check_failed", "project", project, "error", err)
 	}
 	return built
 }
 
+// warnOnce logs msg the first time it is called for key (until the next
+// successful check of the project resets it).
+func (c *Collector) warnOnce(key, msg string, args ...any) {
+	c.mu.Lock()
+	defer c.mu.Unlock()
+	c.warnOnceLocked(key, msg, args...)
+}
+
+func (c *Collector) warnOnceLocked(key, msg string, args ...any) {
+	if c.warned[key] || c.log == nil {
+		return
+	}
+	c.warned[key] = true
+	c.log.Warn(msg, args...)
+}
+
 // fileStamps summarises size and mtime of the comma-separated files, so a
 // changed file changes the string.
 func fileStamps(list string) string {
diff --git a/internal/agent/inventory/collector_test.go b/internal/agent/inventory/collector_test.go
index a0ca78e..2feb70d 100644
--- a/internal/agent/inventory/collector_test.go
+++ b/internal/agent/inventory/collector_test.go
@@ -290,3 +290,22 @@ func TestSnapshot_BuildCheckFailureIsNotFatalAndRetriesLater(t *testing.T) {
 	assert.Equal(t, 2, check.calls)
 	assert.Equal(t, 1, strings.Count(logs.String(), "compose_build_check_failed"), "logged once per project")
 }
+
+func TestSnapshot_ServiceAbsentFromConfigFailsClosed(t *testing.T) {
+	check := &fakeBuildCheck{built: map[string]bool{"db": false}} // "web" is missing
+	c, _ := buildCollector(t, check, "/s/app/compose.yaml")
+	var logs bytes.Buffer
+	c.log = slog.New(slog.NewTextHandler(&logs, nil))
+
+	for range 2 {
+		got, err := c.Snapshot(context.Background())
+		require.NoError(t, err)
+		byName := map[string]protocol.Service{}
+		for _, s := range got {
+			byName[s.ComposeService] = s
+		}
+		assert.True(t, byName["web"].Built, "an unknown service is not offered for update")
+		assert.False(t, byName["db"].Built)
+	}
+	assert.Equal(t, 1, strings.Count(logs.String(), "compose_service_not_in_config"), "logged once per project")
+}
diff --git a/internal/agent/updater/build.go b/internal/agent/updater/build.go
index 81798ce..4433fbc 100644
--- a/internal/agent/updater/build.go
+++ b/internal/agent/updater/build.go
@@ -49,7 +49,9 @@ func NewBuildChecker(cli SelfInspector, selfID string, run OutputRunner) *BuildC
 	return &BuildChecker{cli: cli, selfID: selfID, run: run}
 }
 
-// BuiltServices returns the services of project that have a build: section.
+// BuiltServices returns every service of project (all profiles) mapped to
+// whether it has a build: section. A service that is not a key is not in the
+// project's configuration.
 // The arguments are the labels of one of the project's containers. Files that
 // are not inside the agent's read-write same-path mounts are refused.
 func (b *BuildChecker) BuiltServices(ctx context.Context, project, workingDir, configFilesLabel, envFileLabel string) (map[string]bool, error) {
@@ -77,7 +79,9 @@ func (b *BuildChecker) BuiltServices(ctx context.Context, project, workingDir, c
 // already checked.
 func (b *BuildChecker) builtServices(ctx context.Context, project, workingDir string, files, envs []string) (map[string]bool, error) {
 	args := composeBase(project, workingDir, files, envs)
-	args = append(args, "config", "--format", "json")
+	// Without --profile * compose omits services whose profile is not active,
+	// and a built service behind a profile would read as absent.
+	args = append(args, "--profile", "*", "config", "--format", "json")
 	raw, err := b.run(ctx, workingDir, args...)
 	if err != nil {
 		return nil, fmt.Errorf("docker compose config: %w", err)
diff --git a/internal/agent/updater/build_test.go b/internal/agent/updater/build_test.go
index 273e7ee..9c863c7 100644
--- a/internal/agent/updater/build_test.go
+++ b/internal/agent/updater/build_test.go
@@ -27,7 +27,7 @@ func TestBuildChecker_BuiltServices(t *testing.T) {
 		assert.Equal(t, map[string]bool{"web": true, "db": false, "x": false}, got)
 		require.Len(t, o.cmds, 1)
 		assert.Equal(t, stack, o.cmds[0].dir)
-		assert.Equal(t, []string{"compose", "-p", "app", "--project-directory", stack, "-f", filepath.Join(stack, "compose.yaml"), "config", "--format", "json"}, o.cmds[0].args)
+		assert.Equal(t, []string{"compose", "-p", "app", "--project-directory", stack, "-f", filepath.Join(stack, "compose.yaml"), "--profile", "*", "config", "--format", "json"}, o.cmds[0].args)
 	})
 	t.Run("files outside the roots are refused without running docker", func(t *testing.T) {
 		o := &outRunner{json: plainConfig}
diff --git a/internal/agent/updater/compose.go b/internal/agent/updater/compose.go
index aebbb4d..1e20aac 100644
--- a/internal/agent/updater/compose.go
+++ b/internal/agent/updater/compose.go
@@ -138,7 +138,11 @@ func (e *ComposeExecutor) Execute(ctx context.Context, job protocol.JobStart, ou
 	if err != nil {
 		return "", err
 	}
-	if built[service] {
+	isBuilt, known := built[service]
+	if !known {
+		return "", fmt.Errorf("service %s not found in compose config", service)
+	}
+	if isBuilt {
 		return "", fmt.Errorf("service %s is built from source (build:), not updated", service)
 	}
 
diff --git a/internal/agent/updater/compose_test.go b/internal/agent/updater/compose_test.go
index b4172c9..ab9b637 100644
--- a/internal/agent/updater/compose_test.go
+++ b/internal/agent/updater/compose_test.go
@@ -124,7 +124,20 @@ func TestComposeExecutor(t *testing.T) {
 		_, err := setup(fakeCompose{rw, []container.Summary{ct}}, &fakeDist{digest: d}, rec).Execute(context.Background(), job, io.Discard)
 		require.NoError(t, err)
 		require.Len(t, outr.cmds, 1)
-		assert.Equal(t, ranCmd{stack, []string{"compose", "-p", "slusk", "--project-directory", stack, "-f", filepath.Join(stack, "compose.yaml"), "config", "--format", "json"}}, outr.cmds[0])
+		assert.Equal(t, ranCmd{stack, []string{"compose", "-p", "slusk", "--project-directory", stack, "-f", filepath.Join(stack, "compose.yaml"), "--profile", "*", "config", "--format", "json"}}, outr.cmds[0])
+	})
+	t.Run("service missing from the config is refused", func(t *testing.T) {
+		t.Cleanup(cleanOverride)
+		rec := &recorder{}
+		e := setup(fakeCompose{rw, []container.Summary{ct}}, &fakeDist{digest: d}, rec)
+		outr.json = `{"services":{"db":{"image":"y"}}}`
+		dist := &fakeDist{digest: d}
+		e.resolve = NewResolver(dist, nil)
+		_, err := e.Execute(context.Background(), job, io.Discard)
+		assert.EqualError(t, err, "service web not found in compose config")
+		assert.Empty(t, rec.cmds)
+		assert.Empty(t, dist.refs, "nothing resolved")
+		assert.NoFileExists(t, overridePath)
 	})
 	t.Run("build check failure stops the job", func(t *testing.T) {
 		t.Cleanup(cleanOverride)
@@ -140,13 +153,16 @@ func TestComposeExecutor(t *testing.T) {
 		t.Cleanup(cleanOverride)
 		envFile := filepath.Join(stack, ".env.prod")
 		require.NoError(t, os.WriteFile(envFile, []byte("A=1\n"), 0o644))
+		t.Cleanup(func() { os.Remove(envFile); os.Remove(filepath.Join(stack, ".env.local")) })
+		envFile2 := filepath.Join(stack, ".env.local")
+		require.NoError(t, os.WriteFile(envFile2, []byte("B=2\n"), 0o644))
 		withEnv := container.Summary{Labels: map[string]string{
-			labelWorkingDir: stack, labelConfigFiles: filepath.Join(stack, "compose.yaml"), labelEnvFile: envFile,
+			labelWorkingDir: stack, labelConfigFiles: filepath.Join(stack, "compose.yaml"), labelEnvFile: envFile + "," + envFile2,
 		}}
 		rec := &recorder{}
 		_, err := setup(fakeCompose{rw, []container.Summary{withEnv}}, &fakeDist{digest: d}, rec).Execute(context.Background(), job, io.Discard)
 		require.NoError(t, err)
-		prefix := []string{"compose", "-p", "slusk", "--project-directory", stack, "--env-file", envFile}
+		prefix := []string{"compose", "-p", "slusk", "--project-directory", stack, "--env-file", envFile, "--env-file", envFile2}
 		require.Len(t, outr.cmds, 1)
 		assert.Equal(t, prefix, outr.cmds[0].args[:len(prefix)])
 		require.Len(t, rec.cmds, 2)