diff --git a/compiler/rustc_mir_build/src/check_unsafety.rs b/compiler/rustc_mir_build/src/check_unsafety.rs
index 8c2c81c8628fc..c1866b9a43791 100644
--- a/compiler/rustc_mir_build/src/check_unsafety.rs
+++ b/compiler/rustc_mir_build/src/check_unsafety.rs
@@ -153,6 +153,11 @@ impl<'a, 'tcx> Visitor<'a, 'tcx> for UnsafetyVisitor<'a, 'tcx> {
             ExprKind::InlineAsm { .. } | ExprKind::LlvmInlineAsm { .. } => {
                 self.requires_unsafe(expr.span, UseOfInlineAssembly);
             }
+            ExprKind::Deref { arg } => {
+                if self.thir[arg].ty.is_unsafe_ptr() {
+                    self.requires_unsafe(expr.span, DerefOfRawPointer);
+                }
+            }
             _ => {}
         }
 
@@ -203,7 +208,6 @@ enum UnsafeOpKind {
     UseOfMutableStatic,
     #[allow(dead_code)] // FIXME
     UseOfExternStatic,
-    #[allow(dead_code)] // FIXME
     DerefOfRawPointer,
     #[allow(dead_code)] // FIXME
     AssignToDroppingUnionField,
diff --git a/src/test/ui/generator/issue-45729-unsafe-in-generator.stderr b/src/test/ui/generator/issue-45729-unsafe-in-generator.mir.stderr
similarity index 90%
rename from src/test/ui/generator/issue-45729-unsafe-in-generator.stderr
rename to src/test/ui/generator/issue-45729-unsafe-in-generator.mir.stderr
index 0bd3dbf6863c5..3afbea07931d4 100644
--- a/src/test/ui/generator/issue-45729-unsafe-in-generator.stderr
+++ b/src/test/ui/generator/issue-45729-unsafe-in-generator.mir.stderr
@@ -1,5 +1,5 @@
 error[E0133]: dereference of raw pointer is unsafe and requires unsafe function or block
-  --> $DIR/issue-45729-unsafe-in-generator.rs:5:9
+  --> $DIR/issue-45729-unsafe-in-generator.rs:8:9
    |
 LL |         *(1 as *mut u32) = 42;
    |         ^^^^^^^^^^^^^^^^^^^^^ dereference of raw pointer
diff --git a/src/test/ui/generator/issue-45729-unsafe-in-generator.rs b/src/test/ui/generator/issue-45729-unsafe-in-generator.rs
index 638a1994bb5ed..379c36d2ca321 100644
--- a/src/test/ui/generator/issue-45729-unsafe-in-generator.rs
+++ b/src/test/ui/generator/issue-45729-unsafe-in-generator.rs
@@ -1,3 +1,6 @@
+// revisions: mir thir
+// [thir]compile-flags: -Z thir-unsafeck
+
 #![feature(generators)]
 
 fn main() {
diff --git a/src/test/ui/generator/issue-45729-unsafe-in-generator.thir.stderr b/src/test/ui/generator/issue-45729-unsafe-in-generator.thir.stderr
new file mode 100644
index 0000000000000..a0905f98ca7c6
--- /dev/null
+++ b/src/test/ui/generator/issue-45729-unsafe-in-generator.thir.stderr
@@ -0,0 +1,11 @@
+error[E0133]: dereference of raw pointer is unsafe and requires unsafe function or block
+  --> $DIR/issue-45729-unsafe-in-generator.rs:8:9
+   |
+LL |         *(1 as *mut u32) = 42;
+   |         ^^^^^^^^^^^^^^^^ dereference of raw pointer
+   |
+   = note: raw pointers may be NULL, dangling or unaligned; they can violate aliasing rules and cause data races: all of these are undefined behavior
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0133`.
diff --git a/src/test/ui/issues/issue-47412.stderr b/src/test/ui/issues/issue-47412.mir.stderr
similarity index 91%
rename from src/test/ui/issues/issue-47412.stderr
rename to src/test/ui/issues/issue-47412.mir.stderr
index aebcbf0746305..96e50ba67991c 100644
--- a/src/test/ui/issues/issue-47412.stderr
+++ b/src/test/ui/issues/issue-47412.mir.stderr
@@ -1,5 +1,5 @@
 error[E0133]: access to union field is unsafe and requires unsafe function or block
-  --> $DIR/issue-47412.rs:11:11
+  --> $DIR/issue-47412.rs:14:11
    |
 LL |     match u.void {}
    |           ^^^^^^ access to union field
@@ -7,7 +7,7 @@ LL |     match u.void {}
    = note: the field may not be properly initialized: using uninitialized data will cause undefined behavior
 
 error[E0133]: dereference of raw pointer is unsafe and requires unsafe function or block
-  --> $DIR/issue-47412.rs:17:11
+  --> $DIR/issue-47412.rs:21:11
    |
 LL |     match *ptr {}
    |           ^^^^ dereference of raw pointer
diff --git a/src/test/ui/issues/issue-47412.rs b/src/test/ui/issues/issue-47412.rs
index 2d1ea72280b2d..d395285eee0a0 100644
--- a/src/test/ui/issues/issue-47412.rs
+++ b/src/test/ui/issues/issue-47412.rs
@@ -1,3 +1,6 @@
+// revisions: mir thir
+// [thir]compile-flags: -Z thir-unsafeck
+
 #[derive(Copy, Clone)]
 enum Void {}
 
@@ -9,7 +12,8 @@ fn union_field() {
     union Union { unit: (), void: Void }
     let u = Union { unit: () };
     match u.void {}
-    //~^ ERROR access to union field is unsafe
+    //[mir]~^ ERROR access to union field is unsafe
+    // FIXME(thir-unsafeck): AccessToUnionField unimplemented
 }
 
 fn raw_ptr_deref() {
diff --git a/src/test/ui/issues/issue-47412.thir.stderr b/src/test/ui/issues/issue-47412.thir.stderr
new file mode 100644
index 0000000000000..2d6004b7911d6
--- /dev/null
+++ b/src/test/ui/issues/issue-47412.thir.stderr
@@ -0,0 +1,11 @@
+error[E0133]: dereference of raw pointer is unsafe and requires unsafe function or block
+  --> $DIR/issue-47412.rs:21:11
+   |
+LL |     match *ptr {}
+   |           ^^^^ dereference of raw pointer
+   |
+   = note: raw pointers may be NULL, dangling or unaligned; they can violate aliasing rules and cause data races: all of these are undefined behavior
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0133`.
diff --git a/src/test/ui/traits/safety-fn-body.stderr b/src/test/ui/traits/safety-fn-body.mir.stderr
similarity index 92%
rename from src/test/ui/traits/safety-fn-body.stderr
rename to src/test/ui/traits/safety-fn-body.mir.stderr
index 0aeb186828eea..ea7b2048e836f 100644
--- a/src/test/ui/traits/safety-fn-body.stderr
+++ b/src/test/ui/traits/safety-fn-body.mir.stderr
@@ -1,5 +1,5 @@
 error[E0133]: dereference of raw pointer is unsafe and requires unsafe function or block
-  --> $DIR/safety-fn-body.rs:11:9
+  --> $DIR/safety-fn-body.rs:14:9
    |
 LL |         *self += 1;
    |         ^^^^^^^^^^ dereference of raw pointer
diff --git a/src/test/ui/traits/safety-fn-body.rs b/src/test/ui/traits/safety-fn-body.rs
index df5277473056b..2cc4fe1b344a4 100644
--- a/src/test/ui/traits/safety-fn-body.rs
+++ b/src/test/ui/traits/safety-fn-body.rs
@@ -1,6 +1,9 @@
 // Check that an unsafe impl does not imply that unsafe actions are
 // legal in the methods.
 
+// revisions: mir thir
+// [thir]compile-flags: -Z thir-unsafeck
+
 unsafe trait UnsafeTrait : Sized {
     fn foo(self) { }
 }
diff --git a/src/test/ui/traits/safety-fn-body.thir.stderr b/src/test/ui/traits/safety-fn-body.thir.stderr
new file mode 100644
index 0000000000000..94a1a2a03cdf2
--- /dev/null
+++ b/src/test/ui/traits/safety-fn-body.thir.stderr
@@ -0,0 +1,11 @@
+error[E0133]: dereference of raw pointer is unsafe and requires unsafe function or block
+  --> $DIR/safety-fn-body.rs:14:9
+   |
+LL |         *self += 1;
+   |         ^^^^^ dereference of raw pointer
+   |
+   = note: raw pointers may be NULL, dangling or unaligned; they can violate aliasing rules and cause data races: all of these are undefined behavior
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0133`.
diff --git a/src/test/ui/unsafe/issue-45087-unreachable-unsafe.stderr b/src/test/ui/unsafe/issue-45087-unreachable-unsafe.mir.stderr
similarity index 90%
rename from src/test/ui/unsafe/issue-45087-unreachable-unsafe.stderr
rename to src/test/ui/unsafe/issue-45087-unreachable-unsafe.mir.stderr
index 88322c3a0a684..33f762ccf6301 100644
--- a/src/test/ui/unsafe/issue-45087-unreachable-unsafe.stderr
+++ b/src/test/ui/unsafe/issue-45087-unreachable-unsafe.mir.stderr
@@ -1,5 +1,5 @@
 error[E0133]: dereference of raw pointer is unsafe and requires unsafe function or block
-  --> $DIR/issue-45087-unreachable-unsafe.rs:3:5
+  --> $DIR/issue-45087-unreachable-unsafe.rs:6:5
    |
 LL |     *(1 as *mut u32) = 42;
    |     ^^^^^^^^^^^^^^^^^^^^^ dereference of raw pointer
diff --git a/src/test/ui/unsafe/issue-45087-unreachable-unsafe.rs b/src/test/ui/unsafe/issue-45087-unreachable-unsafe.rs
index 5edf7a47e2f67..071cea8fbd78b 100644
--- a/src/test/ui/unsafe/issue-45087-unreachable-unsafe.rs
+++ b/src/test/ui/unsafe/issue-45087-unreachable-unsafe.rs
@@ -1,3 +1,6 @@
+// revisions: mir thir
+// [thir]compile-flags: -Z thir-unsafeck
+
 fn main() {
     return;
     *(1 as *mut u32) = 42;
diff --git a/src/test/ui/unsafe/issue-45087-unreachable-unsafe.thir.stderr b/src/test/ui/unsafe/issue-45087-unreachable-unsafe.thir.stderr
new file mode 100644
index 0000000000000..b89401ce83706
--- /dev/null
+++ b/src/test/ui/unsafe/issue-45087-unreachable-unsafe.thir.stderr
@@ -0,0 +1,11 @@
+error[E0133]: dereference of raw pointer is unsafe and requires unsafe function or block
+  --> $DIR/issue-45087-unreachable-unsafe.rs:6:5
+   |
+LL |     *(1 as *mut u32) = 42;
+   |     ^^^^^^^^^^^^^^^^ dereference of raw pointer
+   |
+   = note: raw pointers may be NULL, dangling or unaligned; they can violate aliasing rules and cause data races: all of these are undefined behavior
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0133`.
diff --git a/src/test/ui/unsafe/unsafe-fn-assign-deref-ptr.stderr b/src/test/ui/unsafe/unsafe-fn-assign-deref-ptr.mir.stderr
similarity index 90%
rename from src/test/ui/unsafe/unsafe-fn-assign-deref-ptr.stderr
rename to src/test/ui/unsafe/unsafe-fn-assign-deref-ptr.mir.stderr
index b2a30f81e058a..fee645e4118de 100644
--- a/src/test/ui/unsafe/unsafe-fn-assign-deref-ptr.stderr
+++ b/src/test/ui/unsafe/unsafe-fn-assign-deref-ptr.mir.stderr
@@ -1,5 +1,5 @@
 error[E0133]: dereference of raw pointer is unsafe and requires unsafe function or block
-  --> $DIR/unsafe-fn-assign-deref-ptr.rs:2:5
+  --> $DIR/unsafe-fn-assign-deref-ptr.rs:5:5
    |
 LL |     *p = 0;
    |     ^^^^^^ dereference of raw pointer
diff --git a/src/test/ui/unsafe/unsafe-fn-assign-deref-ptr.rs b/src/test/ui/unsafe/unsafe-fn-assign-deref-ptr.rs
index 91264e790c8db..a94e94375ae6a 100644
--- a/src/test/ui/unsafe/unsafe-fn-assign-deref-ptr.rs
+++ b/src/test/ui/unsafe/unsafe-fn-assign-deref-ptr.rs
@@ -1,3 +1,6 @@
+// revisions: mir thir
+// [thir]compile-flags: -Z thir-unsafeck
+
 fn f(p: *mut u8) {
     *p = 0; //~ ERROR dereference of raw pointer is unsafe
     return;
diff --git a/src/test/ui/unsafe/unsafe-fn-assign-deref-ptr.thir.stderr b/src/test/ui/unsafe/unsafe-fn-assign-deref-ptr.thir.stderr
new file mode 100644
index 0000000000000..498d26d30ffcf
--- /dev/null
+++ b/src/test/ui/unsafe/unsafe-fn-assign-deref-ptr.thir.stderr
@@ -0,0 +1,11 @@
+error[E0133]: dereference of raw pointer is unsafe and requires unsafe function or block
+  --> $DIR/unsafe-fn-assign-deref-ptr.rs:5:5
+   |
+LL |     *p = 0;
+   |     ^^ dereference of raw pointer
+   |
+   = note: raw pointers may be NULL, dangling or unaligned; they can violate aliasing rules and cause data races: all of these are undefined behavior
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0133`.
diff --git a/src/test/ui/unsafe/unsafe-fn-deref-ptr.stderr b/src/test/ui/unsafe/unsafe-fn-deref-ptr.mir.stderr
similarity index 91%
rename from src/test/ui/unsafe/unsafe-fn-deref-ptr.stderr
rename to src/test/ui/unsafe/unsafe-fn-deref-ptr.mir.stderr
index 98cb7b876f802..a26149924458c 100644
--- a/src/test/ui/unsafe/unsafe-fn-deref-ptr.stderr
+++ b/src/test/ui/unsafe/unsafe-fn-deref-ptr.mir.stderr
@@ -1,5 +1,5 @@
 error[E0133]: dereference of raw pointer is unsafe and requires unsafe function or block
-  --> $DIR/unsafe-fn-deref-ptr.rs:2:12
+  --> $DIR/unsafe-fn-deref-ptr.rs:5:12
    |
 LL |     return *p;
    |            ^^ dereference of raw pointer
diff --git a/src/test/ui/unsafe/unsafe-fn-deref-ptr.rs b/src/test/ui/unsafe/unsafe-fn-deref-ptr.rs
index 46445aa261dc1..dc989535bd650 100644
--- a/src/test/ui/unsafe/unsafe-fn-deref-ptr.rs
+++ b/src/test/ui/unsafe/unsafe-fn-deref-ptr.rs
@@ -1,3 +1,6 @@
+// revisions: mir thir
+// [thir]compile-flags: -Z thir-unsafeck
+
 fn f(p: *const u8) -> u8 {
     return *p; //~ ERROR dereference of raw pointer is unsafe
 }
diff --git a/src/test/ui/unsafe/unsafe-fn-deref-ptr.thir.stderr b/src/test/ui/unsafe/unsafe-fn-deref-ptr.thir.stderr
new file mode 100644
index 0000000000000..6897e4e691ad0
--- /dev/null
+++ b/src/test/ui/unsafe/unsafe-fn-deref-ptr.thir.stderr
@@ -0,0 +1,11 @@
+error[E0133]: dereference of raw pointer is unsafe and requires unsafe function or block
+  --> $DIR/unsafe-fn-deref-ptr.rs:5:12
+   |
+LL |     return *p;
+   |            ^^ dereference of raw pointer
+   |
+   = note: raw pointers may be NULL, dangling or unaligned; they can violate aliasing rules and cause data races: all of these are undefined behavior
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0133`.
diff --git a/src/test/ui/unsafe/unsafe-unstable-const-fn.stderr b/src/test/ui/unsafe/unsafe-unstable-const-fn.mir.stderr
similarity index 90%
rename from src/test/ui/unsafe/unsafe-unstable-const-fn.stderr
rename to src/test/ui/unsafe/unsafe-unstable-const-fn.mir.stderr
index 410d8d3fb4024..99808495ea675 100644
--- a/src/test/ui/unsafe/unsafe-unstable-const-fn.stderr
+++ b/src/test/ui/unsafe/unsafe-unstable-const-fn.mir.stderr
@@ -1,5 +1,5 @@
 error[E0133]: dereference of raw pointer is unsafe and requires unsafe function or block
-  --> $DIR/unsafe-unstable-const-fn.rs:8:5
+  --> $DIR/unsafe-unstable-const-fn.rs:11:5
    |
 LL |     *a == b
    |     ^^ dereference of raw pointer
diff --git a/src/test/ui/unsafe/unsafe-unstable-const-fn.rs b/src/test/ui/unsafe/unsafe-unstable-const-fn.rs
index c7120e0500725..0476759ca6d98 100644
--- a/src/test/ui/unsafe/unsafe-unstable-const-fn.rs
+++ b/src/test/ui/unsafe/unsafe-unstable-const-fn.rs
@@ -1,3 +1,6 @@
+// revisions: mir thir
+// [thir]compile-flags: -Z thir-unsafeck
+
 #![stable(feature = "foo", since = "1.33.0")]
 #![feature(staged_api)]
 #![feature(const_raw_ptr_deref)]
diff --git a/src/test/ui/unsafe/unsafe-unstable-const-fn.thir.stderr b/src/test/ui/unsafe/unsafe-unstable-const-fn.thir.stderr
new file mode 100644
index 0000000000000..49d6a96860b90
--- /dev/null
+++ b/src/test/ui/unsafe/unsafe-unstable-const-fn.thir.stderr
@@ -0,0 +1,11 @@
+error[E0133]: dereference of raw pointer is unsafe and requires unsafe function or block
+  --> $DIR/unsafe-unstable-const-fn.rs:11:5
+   |
+LL |     *a == b
+   |     ^^ dereference of raw pointer
+   |
+   = note: raw pointers may be NULL, dangling or unaligned; they can violate aliasing rules and cause data races: all of these are undefined behavior
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0133`.