diff --git a/ingestion/internal/pipeline/pipeline.go b/ingestion/internal/pipeline/pipeline.go
index cd4ec03..eab1e3e 100644
--- a/ingestion/internal/pipeline/pipeline.go
+++ b/ingestion/internal/pipeline/pipeline.go
@@ -53,11 +53,18 @@ func Run(ctx context.Context, cfg Config, brainDir, content, source string, dryR
 	var err error
 	if cfg.Wing != "" {
 		// A source slug is a page's graph identity: refuse to take over a slug
-		// that lives anywhere but this wing's own sources/.
-		if existing, found, ferr := wiki.FindSlug(brainDir, wiki.Slug(source)); ferr != nil {
+		// that lives anywhere but this wing's own sources/ — including when
+		// this wing's own page of that name also exists.
+		slug := wiki.Slug(source)
+		own := "wiki/" + cfg.Wing + "/sources/" + slug + ".md"
+		existing, ferr := wiki.FindSlugs(brainDir, slug)
+		if ferr != nil {
 			return Result{}, fmt.Errorf("check source slug: %w", ferr)
-		} else if own := "wiki/" + cfg.Wing + "/sources/" + wiki.Slug(source) + ".md"; found && existing != own {
-			return Result{}, fmt.Errorf("source slug %q is already used by %s", wiki.Slug(source), existing)
+		}
+		for _, p := range existing {
+			if p != own {
+				return Result{}, fmt.Errorf("source slug %q is already used by %s", slug, p)
+			}
 		}
 		inventory, err = wiki.LoadWingInventory(brainDir, cfg.Wing)
 	} else {
diff --git a/ingestion/internal/pipeline/wing_layout_test.go b/ingestion/internal/pipeline/wing_layout_test.go
index 5f5b240..d53b514 100644
--- a/ingestion/internal/pipeline/wing_layout_test.go
+++ b/ingestion/internal/pipeline/wing_layout_test.go
@@ -140,3 +140,17 @@ func listAll(t *testing.T, dir string) []string {
 	_ = filepath.WalkDir(dir, func(p string, _ os.DirEntry, _ error) error { out = append(out, p); return nil })
 	return out
 }
+
+// The first match must not hide a second one: this wing's own page of the name
+// exists AND a page of the same name lives elsewhere.
+func TestRun_ASlugUsedInTwoPlacesIsRefusedEvenWhenTheOwnPageIsOneOfThem(t *testing.T) {
+	dir := t.TempDir()
+	require.NoError(t, os.MkdirAll(filepath.Join(dir, "wiki/web-clip/sources"), 0o755))
+	require.NoError(t, os.WriteFile(filepath.Join(dir, "wiki/web-clip/sources/talk.md"), []byte("---\ntitle: Talk\n---\nown"), 0o644))
+	require.NoError(t, os.MkdirAll(filepath.Join(dir, "wiki/entities"), 0o755))
+	require.NoError(t, os.WriteFile(filepath.Join(dir, "wiki/entities/talk.md"), []byte("---\ntitle: Talk\n---\nan entity"), 0o644))
+
+	_, err := Run(context.Background(), wingCfg("web-clip", sourceEntityConcept()...), dir, "body", "talk", false)
+	require.Error(t, err)
+	assert.Contains(t, err.Error(), "already used")
+}
diff --git a/ingestion/internal/wiki/findslug_test.go b/ingestion/internal/wiki/findslug_test.go
index bb89795..92202a3 100644
--- a/ingestion/internal/wiki/findslug_test.go
+++ b/ingestion/internal/wiki/findslug_test.go
@@ -16,37 +16,41 @@ func put(t *testing.T, dir, rel string) {
 	require.NoError(t, os.WriteFile(full, []byte("---\ntitle: x\n---\n"), 0o644))
 }
 
-func TestFindSlug(t *testing.T) {
+func TestFindSlugs(t *testing.T) {
 	dir := t.TempDir()
 	put(t, dir, "wiki/sources/legacy-src.md")
 	put(t, dir, "wiki/concepts/a-concept.md")
 	put(t, dir, "wiki/entities/an-entity.md")
 	put(t, dir, "wiki/homelab/failures/in-a-hall.md")
 	put(t, dir, "wiki/web-clip/sources/a-clip.md")
+	// One slug in two places: the first hit must not hide the second.
+	put(t, dir, "wiki/sources/shared-slug.md")
+	put(t, dir, "wiki/entities/shared-slug.md")
+	put(t, dir, "wiki/aaa/facts/shared-slug.md")
 
 	tests := []struct {
 		slug string
-		want string
+		want []string
 	}{
-		{"legacy-src", "wiki/sources/legacy-src.md"},
-		{"a-concept", "wiki/concepts/a-concept.md"},
-		{"an-entity", "wiki/entities/an-entity.md"},
-		{"in-a-hall", "wiki/homelab/failures/in-a-hall.md"},
-		{"a-clip", "wiki/web-clip/sources/a-clip.md"},
-		{"nothing-here", ""},
+		{"legacy-src", []string{"wiki/sources/legacy-src.md"}},
+		{"a-concept", []string{"wiki/concepts/a-concept.md"}},
+		{"an-entity", []string{"wiki/entities/an-entity.md"}},
+		{"in-a-hall", []string{"wiki/homelab/failures/in-a-hall.md"}},
+		{"a-clip", []string{"wiki/web-clip/sources/a-clip.md"}},
+		{"shared-slug", []string{"wiki/aaa/facts/shared-slug.md", "wiki/entities/shared-slug.md", "wiki/sources/shared-slug.md"}},
+		{"nothing-here", nil},
 	}
 	for _, tt := range tests {
 		t.Run(tt.slug, func(t *testing.T) {
-			got, found, err := FindSlug(dir, tt.slug)
+			got, err := FindSlugs(dir, tt.slug)
 			require.NoError(t, err)
-			assert.Equal(t, tt.want != "", found)
 			assert.Equal(t, tt.want, got)
 		})
 	}
 }
 
-func TestFindSlug_NoWikiDirIsNotAFinding(t *testing.T) {
-	_, found, err := FindSlug(t.TempDir(), "x")
+func TestFindSlugs_NoWikiDirFindsNothing(t *testing.T) {
+	got, err := FindSlugs(t.TempDir(), "x")
 	require.NoError(t, err)
-	assert.False(t, found)
+	assert.Empty(t, got)
 }
diff --git a/ingestion/internal/wiki/inventory.go b/ingestion/internal/wiki/inventory.go
index b87f5f8..44f8be1 100644
--- a/ingestion/internal/wiki/inventory.go
+++ b/ingestion/internal/wiki/inventory.go
@@ -7,6 +7,7 @@ import (
 	"errors"
 	"fmt"
 	"io/fs"
+	"sort"
 	"strings"
 
 	"github.com/mathiasbq/hyperguild/ingestion/internal/brainfs"
@@ -133,45 +134,46 @@ func LoadWingInventory(brainDir, wing string) (map[PageType][]Entry, error) {
 	return result, nil
 }
 
-// FindSlug returns the brain-relative path of an existing page whose basename is
-// slug, searching the retired dirs (wiki/{sources,concepts,entities}/) and every
-// wing hall (wiki/<wing>/<hall>/). The slug is a page's graph identity, so two
-// pages must not share one.
-func FindSlug(brainDir, slug string) (string, bool, error) {
+// FindSlugs returns the brain-relative path of EVERY existing page whose
+// basename is slug, searching the retired dirs (wiki/{sources,concepts,
+// entities}/) and every wing hall (wiki/<wing>/<hall>/), sorted. The slug is a
+// page's graph identity, so two pages must not share one; returning all of
+// them (not the first) is what lets a caller tell "only my own page" from "my
+// own page and somebody else's".
+func FindSlugs(brainDir, slug string) ([]string, error) {
 	bfs, err := brainfs.Open(brainDir)
 	if err != nil {
-		return "", false, fmt.Errorf("open brain: %w", err)
+		return nil, fmt.Errorf("open brain: %w", err)
 	}
 	defer func() { _ = bfs.Close() }()
 	file := slug + ".md"
-	has := func(dir string) (bool, error) {
+	var found []string
+	check := func(dir string) error {
 		names, err := bfs.ReadDirRegular(dir)
 		if errors.Is(err, fs.ErrNotExist) {
-			return false, nil
+			return nil
 		}
 		if err != nil {
-			return false, err
+			return err
 		}
 		for _, n := range names {
 			if n == file {
-				return true, nil
+				found = append(found, dir+"/"+file)
 			}
 		}
-		return false, nil
+		return nil
 	}
 	for _, d := range []string{"wiki/sources", "wiki/concepts", "wiki/entities"} {
-		if ok, err := has(d); err != nil {
-			return "", false, err
-		} else if ok {
-			return d + "/" + file, true, nil
+		if err := check(d); err != nil {
+			return nil, err
 		}
 	}
 	wings, err := bfs.ReadDirDirs("wiki")
 	if errors.Is(err, fs.ErrNotExist) {
-		return "", false, nil
+		return found, nil
 	}
 	if err != nil {
-		return "", false, err
+		return nil, err
 	}
 	for _, w := range wings {
 		if w == "sources" || w == "concepts" || w == "entities" {
@@ -182,12 +184,11 @@ func FindSlug(brainDir, slug string) (string, bool, error) {
 			continue
 		}
 		for _, h := range halls {
-			if ok, err := has("wiki/" + w + "/" + h); err != nil {
-				return "", false, err
-			} else if ok {
-				return "wiki/" + w + "/" + h + "/" + file, true, nil
+			if err := check("wiki/" + w + "/" + h); err != nil {
+				return nil, err
 			}
 		}
 	}
-	return "", false, nil
+	sort.Strings(found)
+	return found, nil
 }