diff --git a/src/lisp.h b/src/lisp.h
index 2962babb4fe..eaf1c6ce6df 100644
--- a/src/lisp.h
+++ b/src/lisp.h
@@ -1809,7 +1809,8 @@ bool_vector_uchar_data (Lisp_Object a)
 INLINE bool
 bool_vector_bitref (Lisp_Object a, EMACS_INT i)
 {
-  eassume (0 <= i && i < bool_vector_size (a));
+  eassume (0 <= i);
+  eassert (i < bool_vector_size (a));
   return !! (bool_vector_uchar_data (a)[i / BOOL_VECTOR_BITS_PER_CHAR]
 	     & (1 << (i % BOOL_VECTOR_BITS_PER_CHAR)));
 }
@@ -1825,11 +1826,11 @@ bool_vector_ref (Lisp_Object a, EMACS_INT i)
 INLINE void
 bool_vector_set (Lisp_Object a, EMACS_INT i, bool b)
 {
-  unsigned char *addr;
-
-  eassume (0 <= i && i < bool_vector_size (a));
-  addr = &bool_vector_uchar_data (a)[i / BOOL_VECTOR_BITS_PER_CHAR];
+  eassume (0 <= i);
+  eassert (i < bool_vector_size (a));
 
+  unsigned char *addr
+    = &bool_vector_uchar_data (a)[i / BOOL_VECTOR_BITS_PER_CHAR];
   if (b)
     *addr |= 1 << (i % BOOL_VECTOR_BITS_PER_CHAR);
   else