diff --git a/share/libc/string.h b/share/libc/string.h
index c8f5b3d8ec308565caed422e7debcb744c61c755..566b296162caca8aebbd4466043550e300659bab 100644
--- a/share/libc/string.h
+++ b/share/libc/string.h
@@ -66,7 +66,7 @@ extern int memcmp (const void *s1, const void *s2, size_t n);
 
 /*@ requires valid:
          valid_read_or_empty(s, n)
-         || \valid_read(((unsigned char*)s)+(..memchr_off((char*)s,c,n)));
+         || \valid_read(((unsigned char*)s)+(0..memchr_off((char*)s,c,n)));
   @ requires initialization:
         \initialized(((unsigned char*)s)+(0..n - 1))
      || \initialized(((unsigned char*)s)+(0..memchr_off((char*)s,c,n)));
diff --git a/tests/libc/oracle/fc_libc.1.res.oracle b/tests/libc/oracle/fc_libc.1.res.oracle
index 46a7daf3a80476931d58f62f30b136b84c6c7463..8d9222bf04041f16622c88a3d7fe6bbfba9f21c7 100644
--- a/tests/libc/oracle/fc_libc.1.res.oracle
+++ b/tests/libc/oracle/fc_libc.1.res.oracle
@@ -5431,7 +5431,7 @@ char *strrchr(char const *s, int c)
 /*@ requires
       valid:
         valid_read_or_empty(s, n) ∨
-        \valid_read((unsigned char *)s + (.. memchr_off((char *)s, c, n)));
+        \valid_read((unsigned char *)s + (0 .. memchr_off((char *)s, c, n)));
     requires
       initialization:
         \initialized((unsigned char *)s + (0 .. n - 1)) ∨