diff --git a/src/lib.rs b/src/lib.rs
index 880a14b98c80..c34b90877d9d 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -62,5 +62,5 @@ pub use crate::stacked_borrows::{
 /// Insert rustc arguments at the beginning of the argument list that Miri wants to be
 /// set per default, for maximal validation power.
 pub fn miri_default_args() -> &'static [&'static str] {
-    &["-Zalways-encode-mir", "-Zmir-emit-retag", "-Zmir-opt-level=0", "--cfg=miri"]
+    &["-Zalways-encode-mir", "-Zmir-emit-retag", "-Zmir-opt-level=0", "--cfg=miri", "-Cdebug-assertions=on"]
 }
diff --git a/tests/compile-fail/copy_null.rs b/tests/compile-fail/copy_null.rs
index 08391b12ae1b..ce2fbe170e45 100644
--- a/tests/compile-fail/copy_null.rs
+++ b/tests/compile-fail/copy_null.rs
@@ -1,8 +1,14 @@
 //error-pattern: invalid use of NULL pointer
+#![feature(intrinsics)]
+
+// Directly call intrinsic to avoid debug assertions in libstd
+extern "rust-intrinsic" {
+    fn copy_nonoverlapping<T>(src: *const T, dst: *mut T, count: usize);
+}
 
 fn main() {
     let mut data = [0u16; 4];
     let ptr = &mut data[0] as *mut u16;
     // Even copying 0 elements from NULL should error.
-    unsafe { ptr.copy_from(std::ptr::null(), 0); }
+    unsafe { copy_nonoverlapping(std::ptr::null(), ptr, 0); }
 }
diff --git a/tests/compile-fail/copy_overlapping.rs b/tests/compile-fail/copy_overlapping.rs
index 748bccff5d3a..76e1e20d2177 100644
--- a/tests/compile-fail/copy_overlapping.rs
+++ b/tests/compile-fail/copy_overlapping.rs
@@ -1,12 +1,16 @@
-#![feature(core_intrinsics)]
-
 //error-pattern: copy_nonoverlapping called on overlapping ranges
+#![feature(intrinsics)]
+
+// Directly call intrinsic to avoid debug assertions in libstd
+extern "rust-intrinsic" {
+    fn copy_nonoverlapping<T>(src: *const T, dst: *mut T, count: usize);
+}
 
 fn main() {
     let mut data = [0u8; 16];
     unsafe {
         let a = data.as_mut_ptr();
         let b = a.wrapping_offset(1) as *mut _;
-        std::ptr::copy_nonoverlapping(a, b, 2);
+        copy_nonoverlapping(a, b, 2);
     }
 }
diff --git a/tests/compile-fail/copy_unaligned.rs b/tests/compile-fail/copy_unaligned.rs
index e1f243210ade..1a2692978f79 100644
--- a/tests/compile-fail/copy_unaligned.rs
+++ b/tests/compile-fail/copy_unaligned.rs
@@ -1,8 +1,14 @@
 //error-pattern: tried to access memory with alignment 1, but alignment 2 is required
+#![feature(intrinsics)]
+
+// Directly call intrinsic to avoid debug assertions in libstd
+extern "rust-intrinsic" {
+    fn copy_nonoverlapping<T>(src: *const T, dst: *mut T, count: usize);
+}
 
 fn main() {
     let mut data = [0u16; 8];
     let ptr = (&mut data[0] as *mut u16 as *mut u8).wrapping_add(1) as *mut u16;
     // Even copying 0 elements to something unaligned should error
-    unsafe { ptr.copy_from(&data[5], 0); }
+    unsafe { copy_nonoverlapping(&data[5], ptr, 0); }
 }
diff --git a/tests/run-pass/panic/catch_panic.rs b/tests/run-pass/panic/catch_panic.rs
index 722da68b70b2..4d4206923a5e 100644
--- a/tests/run-pass/panic/catch_panic.rs
+++ b/tests/run-pass/panic/catch_panic.rs
@@ -1,4 +1,5 @@
 // ignore-windows: Unwind panicking does not currently work on Windows
+// normalize-stderr-test "[^ ]*libcore/macros/mod.rs[0-9:]*" -> "$$LOC"
 #![feature(never_type)]
 #![allow(const_err)]
 use std::panic::{catch_unwind, AssertUnwindSafe};
@@ -11,7 +12,6 @@ thread_local! {
 }
 
 struct DropTester;
-
 impl Drop for DropTester {
     fn drop(&mut self) {
         DROPPED.with(|c| {
@@ -61,6 +61,11 @@ fn main() {
     test(|_old_val| { let _val = [0, 1, 2][4]; loop {} });
     test(|_old_val| { let _val = 1/0; loop {} });
 
+    // Assertion and debug assertion
+    test(|_old_val| { assert!(false); loop {} });
+    test(|_old_val| { debug_assert!(false); loop {} });
+    test(|_old_val| { unsafe { (1 as *const i32).read() }; loop {} }); // trigger debug-assertion in libstd
+
     // Cleanup: reset to default hook.
     drop(std::panic::take_hook());
 
diff --git a/tests/run-pass/panic/catch_panic.stderr b/tests/run-pass/panic/catch_panic.stderr
index fd9a2f14ec3b..636179beeade 100644
--- a/tests/run-pass/panic/catch_panic.stderr
+++ b/tests/run-pass/panic/catch_panic.stderr
@@ -16,4 +16,10 @@ thread 'main' panicked at 'index out of bounds: the len is 3 but the index is 4'
 Caught panic message (String): index out of bounds: the len is 3 but the index is 4
 thread 'main' panicked at 'attempt to divide by zero', $DIR/catch_panic.rs:62:34
 Caught panic message (String): attempt to divide by zero
+thread 'main' panicked at 'assertion failed: false', $DIR/catch_panic.rs:65:23
+Caught panic message (&str): assertion failed: false
+thread 'main' panicked at 'assertion failed: false', $DIR/catch_panic.rs:66:23
+Caught panic message (&str): assertion failed: false
+thread 'main' panicked at 'attempt to copy from unaligned or null pointer', $LOC
+Caught panic message (String): attempt to copy from unaligned or null pointer
 Success!