diff --git a/cl/cltest/cltest.go b/cl/cltest/cltest.go
index 51f199bf94..c59db54e24 100644
--- a/cl/cltest/cltest.go
+++ b/cl/cltest/cltest.go
@@ -33,6 +33,7 @@ import (
 	"runtime"
 	"slices"
 	"strings"
+	"sync"
 	"testing"
 
 	"github.com/goplus/gogen/packages"
@@ -313,6 +314,21 @@ func testRunAndTestFrom(t *testing.T, pkgDir, relPkg, sel string, opts runOption
 	}
 }
 
+// sharedGoCacheDir returns a per-process go-build cache reused by every
+// captured run. Isolation from the developer cache is preserved (fresh
+// temp dir per test process); sharing across tests avoids re-typechecking
+// the whole dependency graph for each of the ~170 golden dirs.
+var goCacheOnce sync.Once
+var goCacheDir string
+var goCacheErr error
+
+func sharedGoCacheDir() (string, error) {
+	goCacheOnce.Do(func() {
+		goCacheDir, goCacheErr = os.MkdirTemp("", "llgo-gocache-*")
+	})
+	return goCacheDir, goCacheErr
+}
+
 func RunAndCapture(relPkg, pkgDir string) ([]byte, error) {
 	conf := build.NewDefaultConf(build.ModeRun)
 	return RunAndCaptureWithConf(relPkg, pkgDir, conf)
@@ -376,11 +392,10 @@ func runWithConf(relPkg, pkgDir string, conf *build.Config) ([]byte, error) {
 }
 
 func doWithConf(relPkg, pkgDir string, conf *build.Config, action string) ([]byte, error) {
-	cacheDir, err := os.MkdirTemp("", "llgo-gocache-*")
+	cacheDir, err := sharedGoCacheDir()
 	if err != nil {
 		return nil, err
 	}
-	defer os.RemoveAll(cacheDir)
 	oldCache := os.Getenv("GOCACHE")
 	if err := os.Setenv("GOCACHE", cacheDir); err != nil {
 		return nil, err