diff --git a/Makefile b/Makefile
index 971e2be0d..bf3a7ce9f 100644
--- a/Makefile
+++ b/Makefile
@@ -12,7 +12,7 @@
 # limitations under the License.
 
 GO           := GO15VENDOREXPERIMENT=1 go
-FIRST_GOPATH := $(firstword $(subst :, ,$(GOPATH)))
+FIRST_GOPATH := $(firstword $(subst :, ,$(shell $(GO) env GOPATH)))
 PROMU        := $(FIRST_GOPATH)/bin/promu
 pkgs          = $(shell $(GO) list ./... | grep -v /vendor/)