diff --git a/modules/client.go b/modules/client.go
index 1924cd5b4..5b61e5644 100644
--- a/modules/client.go
+++ b/modules/client.go
@@ -90,6 +90,8 @@ func NewClient(cfg ClientConfig) *Client {
 		"GOPRIVATE", mcfg.Private,
 		"GONOPROXY", mcfg.NoProxy,
 		"GOPATH", cfg.CacheDir,
+		// GOCACHE was introduced in Go 1.15. This matches the location derived from GOPATH above.
+		"GOCACHE", filepath.Join(cfg.CacheDir, "pkg", "mod"),
 	)
 
 	logger := cfg.Logger