diff --git a/gopls/internal/regtest/codelens/codelens_test.go b/gopls/internal/regtest/codelens/codelens_test.go
index a2a1ae4558..d89b8e0bd8 100644
--- a/gopls/internal/regtest/codelens/codelens_test.go
+++ b/gopls/internal/regtest/codelens/codelens_test.go
@@ -166,11 +166,16 @@ require golang.org/x/hello v1.3.3
 				if vendoring {
 					env.RunGoCommand("mod", "vendor")
 				}
+				env.Await(env.DoneWithChangeWatchedFiles())
 				env.OpenFile("go.mod")
 				env.ExecuteCodeLensCommand("go.mod", command.CheckUpgrades)
 				d := &protocol.PublishDiagnosticsParams{}
-				env.Await(OnceMet(env.DiagnosticAtRegexpWithMessage("go.mod", `require`, "can be upgraded"),
-					ReadDiagnostics("go.mod", d)))
+				env.Await(
+					OnceMet(
+						env.DiagnosticAtRegexpWithMessage("go.mod", `require`, "can be upgraded"),
+						ReadDiagnostics("go.mod", d),
+					),
+				)
 				env.ApplyQuickFixes("go.mod", d.Diagnostics)
 				env.Await(env.DoneWithChangeWatchedFiles())
 				if got := env.Editor.BufferText("go.mod"); got != wantGoMod {
diff --git a/internal/lsp/cache/load.go b/internal/lsp/cache/load.go
index 5a69875b90..1baa3e5ee2 100644
--- a/internal/lsp/cache/load.go
+++ b/internal/lsp/cache/load.go
@@ -194,7 +194,9 @@ func (s *snapshot) load(ctx context.Context, allowNetwork bool, scopes ...interf
 			continue
 		}
 		// Set the metadata for this package.
-		m, err := s.setMetadata(ctx, packagePath(pkg.PkgPath), pkg, cfg, map[packageID]struct{}{})
+		s.mu.Lock()
+		m, err := s.setMetadataLocked(ctx, packagePath(pkg.PkgPath), pkg, cfg, map[packageID]struct{}{})
+		s.mu.Unlock()
 		if err != nil {
 			return err
 		}
@@ -388,10 +390,10 @@ func getWorkspaceDir(ctx context.Context, h *memoize.Handle, g *memoize.Generati
 	return span.URIFromPath(v.(*workspaceDirData).dir), nil
 }
 
-// setMetadata extracts metadata from pkg and records it in s. It
+// setMetadataLocked extracts metadata from pkg and records it in s. It
 // recurses through pkg.Imports to ensure that metadata exists for all
 // dependencies.
-func (s *snapshot) setMetadata(ctx context.Context, pkgPath packagePath, pkg *packages.Package, cfg *packages.Config, seen map[packageID]struct{}) (*metadata, error) {
+func (s *snapshot) setMetadataLocked(ctx context.Context, pkgPath packagePath, pkg *packages.Package, cfg *packages.Config, seen map[packageID]struct{}) (*metadata, error) {
 	id := packageID(pkg.ID)
 	if _, ok := seen[id]; ok {
 		return nil, errors.Errorf("import cycle detected: %q", id)
@@ -429,7 +431,7 @@ func (s *snapshot) setMetadata(ctx context.Context, pkgPath packagePath, pkg *pa
 		m.goFiles = append(m.goFiles, uri)
 		uris[uri] = struct{}{}
 	}
-	s.updateIDForURIs(id, uris)
+	s.updateIDForURIsLocked(id, uris)
 
 	// TODO(rstambler): is this still necessary?
 	copied := map[packageID]struct{}{
@@ -452,16 +454,14 @@ func (s *snapshot) setMetadata(ctx context.Context, pkgPath packagePath, pkg *pa
 			m.missingDeps[importPkgPath] = struct{}{}
 			continue
 		}
-		if s.noValidMetadataForID(importID) {
-			if _, err := s.setMetadata(ctx, importPkgPath, importPkg, cfg, copied); err != nil {
+		if s.noValidMetadataForIDLocked(importID) {
+			if _, err := s.setMetadataLocked(ctx, importPkgPath, importPkg, cfg, copied); err != nil {
 				event.Error(ctx, "error in dependency", err)
 			}
 		}
 	}
 
 	// Add the metadata to the cache.
-	s.mu.Lock()
-	defer s.mu.Unlock()
 
 	// If we've already set the metadata for this snapshot, reuse it.
 	if original, ok := s.metadata[m.id]; ok && original.valid {
@@ -473,6 +473,11 @@ func (s *snapshot) setMetadata(ctx context.Context, pkgPath packagePath, pkg *pa
 			metadata: m,
 			valid:    true,
 		}
+		// Invalidate any packages we may have associated with this metadata.
+		for _, mode := range []source.ParseMode{source.ParseHeader, source.ParseExported, source.ParseFull} {
+			key := packageKey{mode, m.id}
+			delete(s.packages, key)
+		}
 	}
 
 	// Set the workspace packages. If any of the package's files belong to the
diff --git a/internal/lsp/cache/snapshot.go b/internal/lsp/cache/snapshot.go
index 207be3a437..21ca384de4 100644
--- a/internal/lsp/cache/snapshot.go
+++ b/internal/lsp/cache/snapshot.go
@@ -1114,19 +1114,22 @@ func (s *snapshot) noValidMetadataForURILocked(uri span.URI) bool {
 // noValidMetadataForID reports whether there is no valid metadata for the
 // given ID.
 func (s *snapshot) noValidMetadataForID(id packageID) bool {
-	m := s.getMetadata(id)
+	s.mu.Lock()
+	defer s.mu.Unlock()
+	return s.noValidMetadataForIDLocked(id)
+}
+
+func (s *snapshot) noValidMetadataForIDLocked(id packageID) bool {
+	m := s.metadata[id]
 	return m == nil || !m.valid
 }
 
-// updateIDForURIs adds the given ID to the set of known IDs for the given URI.
+// updateIDForURIsLocked adds the given ID to the set of known IDs for the given URI.
 // Any existing invalid IDs are removed from the set of known IDs. IDs that are
 // not "command-line-arguments" are preferred, so if a new ID comes in for a
 // URI that previously only had "command-line-arguments", the new ID will
 // replace the "command-line-arguments" ID.
-func (s *snapshot) updateIDForURIs(id packageID, uris map[span.URI]struct{}) {
-	s.mu.Lock()
-	defer s.mu.Unlock()
-
+func (s *snapshot) updateIDForURIsLocked(id packageID, uris map[span.URI]struct{}) {
 	for uri := range uris {
 		// Collect the new set of IDs, preserving any valid existing IDs.
 		newIDs := []packageID{id}