diff --git a/Modules/_randommodule.c b/Modules/_randommodule.c
index d96c0371ec7f8e..86e839d6010e92 100644
--- a/Modules/_randommodule.c
+++ b/Modules/_randommodule.c
@@ -177,7 +177,7 @@ _random_Random_random_impl(RandomObject *self)
 /*[clinic end generated code: output=117ff99ee53d755c input=afb2a59cbbb00349]*/
 {
     uint32_t a=genrand_uint32(self)>>5, b=genrand_uint32(self)>>6;
-    return PyFloat_FromDouble((a*67108864.0+b)*(1.0/9007199254740992.0));
+    return PyFloat_FromDouble(((((uint64_t)(a)<<26)|b)|1)*(1.0/9007199254740992.0));    
 }
 
 /* initializes mt[N] with a seed */