diff --git a/Modules/_struct.c b/Modules/_struct.c
index ba8a8ed979e..c1db286b051 100644
--- a/Modules/_struct.c
+++ b/Modules/_struct.c
@@ -856,11 +856,11 @@ bp_double(char *p, PyObject *v, const formatdef *f)
 static int
 bp_bool(char *p, PyObject *v, const formatdef *f)
 {
-    char y;
+    int y;
     y = PyObject_IsTrue(v);
     if (y < 0)
         return -1;
-    memcpy(p, (char *)&y, sizeof y);
+    *p = (char)y;
     return 0;
 }