diff --git a/Dockerfile b/Dockerfile
index 646866d..30453d1 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -8,7 +8,7 @@
 ENV PATH /usr/local/go/bin:$GOPATH/bin:$PATH
 ENV GOROOT_BOOTSTRAP /usr/local/gobootstrap
 ENV CGO_ENABLED=0
-ENV GO_VERSION 1.11.1
+ENV GO_VERSION 1.12
 ENV BUILD_DEPS 'curl bzip2 git gcc patch libc6-dev ca-certificates'
 
 # Fake time
@@ -174,6 +174,10 @@
 COPY --from=builder /usr/local/go /usr/local/go
 COPY --from=builder /tmp/sel_ldr_x86_64 /usr/local/bin
 
+# For implicit GOCACHE (issues 29243 and 29251), set HOME:
+RUN mkdir -p /home/gopher
+ENV HOME /home/gopher
+
 ENV GOPATH /go
 ENV PATH /usr/local/go/bin:$GOPATH/bin:$PATH
 
diff --git a/sandbox.go b/sandbox.go
index 7fb6964..8e21a96 100644
--- a/sandbox.go
+++ b/sandbox.go
@@ -324,7 +324,7 @@
 
 	exe := filepath.Join(tmpDir, "a.out")
 	cmd := exec.Command("go", "build", "-o", exe, in)
-	cmd.Env = []string{"GOOS=nacl", "GOARCH=amd64p32", "GOPATH=" + os.Getenv("GOPATH")}
+	cmd.Env = []string{"GOOS=nacl", "GOARCH=amd64p32", "GOPATH=" + os.Getenv("GOPATH"), "HOME=" + os.Getenv("HOME")}
 	if out, err := cmd.CombinedOutput(); err != nil {
 		if _, ok := err.(*exec.ExitError); ok {
 			// Return compile errors to the user.