diff --git a/src/os/exec/exec.go b/src/os/exec/exec.go
index 8101e71..f0dc7da 100644
--- a/src/os/exec/exec.go
+++ b/src/os/exec/exec.go
@@ -465,6 +465,9 @@
 // The Wait method will return the exit code and release associated resources
 // once the command exits.
 func (c *Cmd) Start() error {
+	if c.Path == "" && c.Err == nil && c.lookPathErr == nil {
+		c.Err = errors.New("exec: no command")
+	}
 	if c.Err != nil || c.lookPathErr != nil {
 		c.closeDescriptors(c.closeAfterStart)
 		c.closeDescriptors(c.closeAfterWait)
diff --git a/src/os/exec/exec_test.go b/src/os/exec/exec_test.go
index c593cbd..9cc14bd 100644
--- a/src/os/exec/exec_test.go
+++ b/src/os/exec/exec_test.go
@@ -1125,3 +1125,11 @@
 		t.Errorf("String(%q, %q) = %q, want %q", "makemeasandwich", "-lettuce", got, want)
 	}
 }
+
+func TestNoPath(t *testing.T) {
+	err := new(exec.Cmd).Start()
+	want := "exec: no command"
+	if err == nil || err.Error() != want {
+		t.Errorf("new(Cmd).Start() = %v, want %q", err, want)
+	}
+}