diff --git a/fxtesting/testing.go b/fxtesting/testing.go
index 2a2318c..0c6b067 100644
--- a/fxtesting/testing.go
+++ b/fxtesting/testing.go
@@ -14,6 +14,14 @@
 	*testing.T
 }
 
+// IsPresubmitMode returns true iff running in short mode.  To enable short mode, run
+// `go test -short`.  Long running tests and integration tests should Skip() themselves if
+// this flag is set.  See https://golang.org/pkg/testing/ for an explanation of the
+// testing package's short flag.
+func IsPresubmitMode() bool {
+	return testing.Short()
+}
+
 // AssertNil raises a fatal error if the error is not nil.
 func (t *T) AssertNil(err error) {
 	if err != nil {