diff --git a/internal/lsp/cache/overlay.go b/internal/lsp/cache/overlay.go
index 42ce1eabe8..dfe868720c 100644
--- a/internal/lsp/cache/overlay.go
+++ b/internal/lsp/cache/overlay.go
@@ -41,10 +41,10 @@ func (o *overlay) Read(ctx context.Context) ([]byte, string, error) {
 	return o.text, o.hash, nil
 }
 
-func (s *session) updateOverlay(ctx context.Context, c source.FileModification) (source.FileKind, error) {
+func (s *session) updateOverlay(ctx context.Context, c source.FileModification) error {
 	// Make sure that the file was not changed on disk.
 	if c.OnDisk {
-		return source.UnknownKind, errors.Errorf("updateOverlay called for an on-disk change: %s", c.URI)
+		return errors.Errorf("updateOverlay called for an on-disk change: %s", c.URI)
 	}
 
 	s.overlayMu.Lock()
@@ -59,18 +59,18 @@ func (s *session) updateOverlay(ctx context.Context, c source.FileModification)
 		kind = source.DetectLanguage(c.LanguageID, c.URI.Filename())
 	default:
 		if !ok {
-			return -1, errors.Errorf("updateOverlay: modifying unopened overlay %v", c.URI)
+			return errors.Errorf("updateOverlay: modifying unopened overlay %v", c.URI)
 		}
 		kind = o.kind
 	}
 	if kind == source.UnknownKind {
-		return -1, errors.Errorf("updateOverlay: unknown file kind for %s", c.URI)
+		return errors.Errorf("updateOverlay: unknown file kind for %s", c.URI)
 	}
 
 	// Closing a file just deletes its overlay.
 	if c.Action == source.Close {
 		delete(s.overlays, c.URI)
-		return kind, nil
+		return nil
 	}
 
 	// If the file is on disk, check if its content is the same as the overlay.
@@ -87,10 +87,10 @@ func (s *session) updateOverlay(ctx context.Context, c source.FileModification)
 	case source.Save:
 		// Make sure the version and content (if present) is the same.
 		if o.version != c.Version {
-			return -1, errors.Errorf("updateOverlay: saving %s at version %v, currently at %v", c.URI, c.Version, o.version)
+			return errors.Errorf("updateOverlay: saving %s at version %v, currently at %v", c.URI, c.Version, o.version)
 		}
 		if c.Text != nil && o.hash != hash {
-			return -1, errors.Errorf("updateOverlay: overlay %s changed on save", c.URI)
+			return errors.Errorf("updateOverlay: overlay %s changed on save", c.URI)
 		}
 		sameContentOnDisk = true
 	}
@@ -103,7 +103,7 @@ func (s *session) updateOverlay(ctx context.Context, c source.FileModification)
 		hash:    hash,
 		saved:   sameContentOnDisk,
 	}
-	return kind, nil
+	return nil
 }
 
 func (s *session) readOverlay(uri span.URI) *overlay {
diff --git a/internal/lsp/cache/session.go b/internal/lsp/cache/session.go
index d421b34fcf..58fe475ecb 100644
--- a/internal/lsp/cache/session.go
+++ b/internal/lsp/cache/session.go
@@ -257,10 +257,8 @@ func (s *session) DidModifyFile(ctx context.Context, c source.FileModification)
 	ctx = telemetry.URI.With(ctx, c.URI)
 
 	// Update overlays only if the file was changed in the editor.
-	var kind source.FileKind
 	if !c.OnDisk {
-		kind, err = s.updateOverlay(ctx, c)
-		if err != nil {
+		if err := s.updateOverlay(ctx, c); err != nil {
 			return nil, err
 		}
 	}
@@ -279,22 +277,10 @@ func (s *session) DidModifyFile(ctx context.Context, c source.FileModification)
 			}
 		}
 		// Make sure that the file is added to the view.
-		f, err := view.getFile(c.URI)
-		if err != nil {
+		if _, err := view.getFile(c.URI); err != nil {
 			return nil, err
 		}
-		// If the file change was on disk, the file kind is not known.
-		if c.OnDisk {
-			// If the file was already known in the snapshot,
-			// then use the already known file kind. Otherwise,
-			// detect the file kind. This should only be needed for file creates.
-			if fh := view.getSnapshot().findFileHandle(f); fh != nil {
-				kind = fh.Identity().Kind
-			} else {
-				kind = source.DetectLanguage("", c.URI.Filename())
-			}
-		}
-		snapshots = append(snapshots, view.invalidateContent(ctx, c.URI, kind, c.Action))
+		snapshots = append(snapshots, view.invalidateContent(ctx, []span.URI{c.URI}, c.Action == source.Save))
 	}
 	return snapshots, nil
 }
diff --git a/internal/lsp/cache/view.go b/internal/lsp/cache/view.go
index e7122d452e..3c2b2ad0e8 100644
--- a/internal/lsp/cache/view.go
+++ b/internal/lsp/cache/view.go
@@ -577,19 +577,20 @@ func (v *view) awaitInitialized(ctx context.Context) error {
 // invalidateContent invalidates the content of a Go file,
 // including any position and type information that depends on it.
 // It returns true if we were already tracking the given file, false otherwise.
-func (v *view) invalidateContent(ctx context.Context, uri span.URI, kind source.FileKind, action source.FileAction) source.Snapshot {
+func (v *view) invalidateContent(ctx context.Context, uris []span.URI, containsFileSave bool) source.Snapshot {
 	// Detach the context so that content invalidation cannot be canceled.
 	ctx = xcontext.Detach(ctx)
 
+	if containsFileSave && len(uris) > 1 {
+		panic("file save among multiple content invalidations")
+	}
+
 	// Cancel all still-running previous requests, since they would be
 	// operating on stale data.
 	//
-	// TODO(rstambler): All actions should lead to cancellation,
-	// but this will only be possible when all text synchronization events
-	// trigger diagnostics.
-	switch action {
-	case source.Save:
-	default:
+	// TODO(rstambler): File saves should also lead to cancellation,
+	// but this will only be possible when they trigger workspace-level diagnostics.
+	if !containsFileSave {
 		v.cancelBackground()
 	}
 
@@ -600,7 +601,7 @@ func (v *view) invalidateContent(ctx context.Context, uri span.URI, kind source.
 	v.snapshotMu.Lock()
 	defer v.snapshotMu.Unlock()
 
-	v.snapshot = v.snapshot.clone(ctx, []span.URI{uri})
+	v.snapshot = v.snapshot.clone(ctx, uris)
 	return v.snapshot
 }