diff --git a/gopls/internal/regtest/workspace/broken_test.go b/gopls/internal/regtest/workspace/broken_test.go
index cd5127ff3a..e88b98b50e 100644
--- a/gopls/internal/regtest/workspace/broken_test.go
+++ b/gopls/internal/regtest/workspace/broken_test.go
@@ -115,3 +115,55 @@ const CompleteMe = 222
 		}
 	})
 }
+
+// Test for golang/go#43186: correcting the module path should fix errors
+// without restarting gopls.
+func TestBrokenWorkspace_WrongModulePath(t *testing.T) {
+	const files = `
+-- go.mod --
+module mod.testx
+
+go 1.18
+-- p/internal/foo/foo.go --
+package foo
+
+const C = 1
+-- p/internal/bar/bar.go --
+package bar
+
+import "mod.test/p/internal/foo"
+
+const D = foo.C + 1
+-- p/internal/bar/bar_test.go --
+package bar_test
+
+import (
+	"mod.test/p/internal/foo"
+	. "mod.test/p/internal/bar"
+)
+
+const E = D + foo.C
+-- p/internal/baz/baz_test.go --
+package baz_test
+
+import (
+	named "mod.test/p/internal/bar"
+)
+
+const F = named.D - 3
+`
+
+	Run(t, files, func(t *testing.T, env *Env) {
+		env.OpenFile("p/internal/bar/bar.go")
+		env.Await(
+			OnceMet(
+				env.DoneWithOpen(),
+				env.DiagnosticAtRegexp("p/internal/bar/bar.go", "\"mod.test/p/internal/foo\""),
+			),
+		)
+		env.OpenFile("go.mod")
+		env.RegexpReplace("go.mod", "mod.testx", "mod.test")
+		env.SaveBuffer("go.mod") // saving triggers a reload
+		env.Await(NoOutstandingDiagnostics())
+	})
+}
diff --git a/internal/lsp/cache/check.go b/internal/lsp/cache/check.go
index 6c02d5348f..6beee1f7be 100644
--- a/internal/lsp/cache/check.go
+++ b/internal/lsp/cache/check.go
@@ -355,6 +355,7 @@ func typeCheckImpl(ctx context.Context, snapshot *snapshot, goFiles, compiledGoF
 			missing, unexpected = filter.ProcessErrors(pkg.typeErrors)
 		}
 		if len(unexpected) != 0 || len(missing) != 0 {
+			// TODO(rfindley): remove this distracting log
 			event.Log(ctx, fmt.Sprintf("falling back to safe trimming due to type errors: %v or still-missing identifiers: %v", unexpected, missing), tag.Package.Of(string(m.ID)))
 			pkg, err = doTypeCheck(ctx, snapshot, goFiles, compiledGoFiles, m, mode, deps, nil)
 			if err != nil {
diff --git a/internal/lsp/cache/load.go b/internal/lsp/cache/load.go
index ca906c8287..8afbb2e4ff 100644
--- a/internal/lsp/cache/load.go
+++ b/internal/lsp/cache/load.go
@@ -635,6 +635,12 @@ func containsFileInWorkspaceLocked(s *snapshot, m *Metadata) bool {
 func computeWorkspacePackagesLocked(s *snapshot, meta *metadataGraph) map[PackageID]PackagePath {
 	workspacePackages := make(map[PackageID]PackagePath)
 	for _, m := range meta.metadata {
+		// Don't consider invalid packages to be workspace packages. Doing so can
+		// result in type-checking and diagnosing packages that no longer exist,
+		// which can lead to memory leaks and confusing errors.
+		if !m.Valid {
+			continue
+		}
 		if !containsPackageLocked(s, m.Metadata) {
 			continue
 		}
diff --git a/internal/lsp/cache/snapshot.go b/internal/lsp/cache/snapshot.go
index 6d3ead5c37..5a51ae13e0 100644
--- a/internal/lsp/cache/snapshot.go
+++ b/internal/lsp/cache/snapshot.go
@@ -1874,13 +1874,8 @@ func (s *snapshot) clone(ctx, bgCtx context.Context, changes map[span.URI]*fileC
 		result.actions.Delete(key)
 	}
 
-	// If the workspace mode has changed, we must delete all metadata, as it
-	// is unusable and may produce confusing or incorrect diagnostics.
 	// If a file has been deleted, we must delete metadata for all packages
 	// containing that file.
-	workspaceModeChanged := s.workspaceMode() != result.workspaceMode()
-
-	// Don't keep package metadata for packages that have lost files.
 	//
 	// TODO(rfindley): why not keep invalid metadata in this case? If we
 	// otherwise allow operate on invalid metadata, why not continue to do so,
@@ -1907,11 +1902,27 @@ func (s *snapshot) clone(ctx, bgCtx context.Context, changes map[span.URI]*fileC
 		result.shouldLoad[k] = v
 	}
 
+	// TODO(rfindley): consolidate the this workspace mode detection with
+	// workspace invalidation.
+	workspaceModeChanged := s.workspaceMode() != result.workspaceMode()
+
+	// We delete invalid metadata in the following cases:
+	// - If we are forcing a reload of metadata.
+	// - If the workspace mode has changed, as stale metadata may produce
+	//   confusing or incorrect diagnostics.
+	//
+	// TODO(rfindley): we should probably also clear metadata if we are
+	// reinitializing the workspace, as otherwise we could leave around a bunch
+	// of irrelevant and duplicate metadata (for example, if the module path
+	// changed). However, this breaks the "experimentalUseInvalidMetadata"
+	// feature, which relies on stale metadata when, for example, a go.mod file
+	// is broken via invalid syntax.
+	deleteInvalidMetadata := forceReloadMetadata || workspaceModeChanged
+
 	// Compute which metadata updates are required. We only need to invalidate
 	// packages directly containing the affected file, and only if it changed in
 	// a relevant way.
 	metadataUpdates := make(map[PackageID]*KnownMetadata)
-	deleteInvalidMetadata := forceReloadMetadata || workspaceModeChanged
 	for k, v := range s.meta.metadata {
 		invalidateMetadata := idsToInvalidate[k]
 
diff --git a/internal/lsp/source/util.go b/internal/lsp/source/util.go
index 262447cf36..78448af417 100644
--- a/internal/lsp/source/util.go
+++ b/internal/lsp/source/util.go
@@ -555,6 +555,8 @@ func IsValidImport(pkgPath, importPkgPath string) bool {
 	if IsCommandLineArguments(string(pkgPath)) {
 		return true
 	}
+	// TODO(rfindley): this is wrong. mod.testx/p should not be able to
+	// import mod.test/internal: https://go.dev/play/p/-Ca6P-E4V4q
 	return strings.HasPrefix(string(pkgPath), string(importPkgPath[:i]))
 }