diff --git a/rust-version b/rust-version
index 7e957fa4257..853c4ff1033 100644
--- a/rust-version
+++ b/rust-version
@@ -1 +1 @@
-fd61d06772d17c6242265d860fbfb5eafd282caa
+7f65393b9abf5e70d0b9a8080558f17c5625bd40
diff --git a/tests/compile-fail/invalid_bool.rs b/tests/compile-fail/invalid_bool.rs
index 23441ea7d4a..6dee9ec3c91 100644
--- a/tests/compile-fail/invalid_bool.rs
+++ b/tests/compile-fail/invalid_bool.rs
@@ -4,5 +4,5 @@
 
 fn main() {
     let b = unsafe { std::mem::transmute::<u8, bool>(2) };
-    let _x = b == true; //~ ERROR interpreting an invalid 8-bit value as a bool
+    let _x = b == true; //~ ERROR interpreting an invalid 8-bit value as a bool: 0x02
 }
diff --git a/tests/compile-fail/invalid_char.rs b/tests/compile-fail/invalid_char.rs
index ab10ab1e217..b240cb22ebe 100644
--- a/tests/compile-fail/invalid_char.rs
+++ b/tests/compile-fail/invalid_char.rs
@@ -3,7 +3,8 @@
 // compile-flags: -Zmiri-disable-alignment-check -Zmiri-disable-stacked-borrows -Zmiri-disable-validation
 
 fn main() {
-    assert!(std::char::from_u32(-1_i32 as u32).is_none());
-    let c = unsafe { std::mem::transmute::<i32, char>(-1) };
-    let _x = c == 'x'; //~ ERROR interpreting an invalid 32-bit value as a char
+    let c = 0xFFFFFFu32;
+    assert!(std::char::from_u32(c).is_none());
+    let c = unsafe { std::mem::transmute::<u32, char>(c) };
+    let _x = c == 'x'; //~ ERROR interpreting an invalid 32-bit value as a char: 0x00ffffff
 }