diff --git a/internal/execenv/execenv.go b/internal/execenv/execenv.go
index bda7fed..eeb8bcf 100644
--- a/internal/execenv/execenv.go
+++ b/internal/execenv/execenv.go
@@ -17,7 +17,7 @@ const execEnvCallbackName = "exec-env"
 func Generate(plugin plugins.Plugin, callbackEnv map[string]string) (env map[string]string, err error) {
 	execEnvPath, err := plugin.CallbackPath(execEnvCallbackName)
 	if err != nil {
-		return env, err
+		return callbackEnv, err
 	}
 
 	var stdout strings.Builder
@@ -27,7 +27,7 @@ func Generate(plugin plugins.Plugin, callbackEnv map[string]string) (env map[str
 	// executing the callback isn't enough. We actually need to source it (.) so
 	// the environment variables get set, and then run `env` so they get printed
 	// to STDOUT.
-	expression := execute.NewExpression(fmt.Sprintf(". %s; env", execEnvPath), []string{})
+	expression := execute.NewExpression(fmt.Sprintf(". \"%s\"; env", execEnvPath), []string{})
 	expression.Env = callbackEnv
 	expression.Stdout = &stdout
 	err = expression.Run()