diff --git a/compiler/rustc_mir/src/transform/const_prop.rs b/compiler/rustc_mir/src/transform/const_prop.rs
index 1c78f5911d526..7d81588c46e13 100644
--- a/compiler/rustc_mir/src/transform/const_prop.rs
+++ b/compiler/rustc_mir/src/transform/const_prop.rs
@@ -1071,9 +1071,9 @@ impl<'mir, 'tcx> MutVisitor<'tcx> for ConstPropagator<'mir, 'tcx> {
     fn visit_operand(&mut self, operand: &mut Operand<'tcx>, location: Location) {
         self.super_operand(operand, location);
 
-        // Only const prop copies and moves on `mir_opt_level=2` as doing so
+        // Only const prop copies and moves on `mir_opt_level=3` as doing so
         // currently slightly increases compile time in some cases.
-        if self.tcx.sess.mir_opt_level() >= 2 {
+        if self.tcx.sess.mir_opt_level() >= 3 {
             self.propagate_operand(operand)
         }
     }
diff --git a/compiler/rustc_mir/src/transform/dest_prop.rs b/compiler/rustc_mir/src/transform/dest_prop.rs
index 305d9426c1860..0822ab73c4c67 100644
--- a/compiler/rustc_mir/src/transform/dest_prop.rs
+++ b/compiler/rustc_mir/src/transform/dest_prop.rs
@@ -127,9 +127,9 @@ pub struct DestinationPropagation;
 
 impl<'tcx> MirPass<'tcx> for DestinationPropagation {
     fn run_pass(&self, tcx: TyCtxt<'tcx>, body: &mut Body<'tcx>) {
-        // Only run at mir-opt-level=2 or higher for now (we don't fix up debuginfo and remove
+        // Only run at mir-opt-level=3 or higher for now (we don't fix up debuginfo and remove
         // storage statements at the moment).
-        if tcx.sess.mir_opt_level() < 2 {
+        if tcx.sess.mir_opt_level() < 3 {
             return;
         }
 
diff --git a/compiler/rustc_mir/src/transform/early_otherwise_branch.rs b/compiler/rustc_mir/src/transform/early_otherwise_branch.rs
index ae9a1ed4680aa..821167fd9f05c 100644
--- a/compiler/rustc_mir/src/transform/early_otherwise_branch.rs
+++ b/compiler/rustc_mir/src/transform/early_otherwise_branch.rs
@@ -26,7 +26,7 @@ pub struct EarlyOtherwiseBranch;
 
 impl<'tcx> MirPass<'tcx> for EarlyOtherwiseBranch {
     fn run_pass(&self, tcx: TyCtxt<'tcx>, body: &mut Body<'tcx>) {
-        if tcx.sess.mir_opt_level() < 2 {
+        if tcx.sess.mir_opt_level() < 3 {
             return;
         }
         trace!("running EarlyOtherwiseBranch on {:?}", body.source);
diff --git a/compiler/rustc_mir/src/transform/inline.rs b/compiler/rustc_mir/src/transform/inline.rs
index ede8c54b20bd6..bc64e89013d05 100644
--- a/compiler/rustc_mir/src/transform/inline.rs
+++ b/compiler/rustc_mir/src/transform/inline.rs
@@ -52,7 +52,7 @@ crate fn is_enabled(tcx: TyCtxt<'_>) -> bool {
         return enabled;
     }
 
-    tcx.sess.mir_opt_level() >= 2
+    tcx.sess.mir_opt_level() >= 3
 }
 
 impl<'tcx> MirPass<'tcx> for Inline {
diff --git a/compiler/rustc_mir/src/transform/match_branches.rs b/compiler/rustc_mir/src/transform/match_branches.rs
index deb9c3d3d4b18..e254f0553aa59 100644
--- a/compiler/rustc_mir/src/transform/match_branches.rs
+++ b/compiler/rustc_mir/src/transform/match_branches.rs
@@ -40,7 +40,7 @@ pub struct MatchBranchSimplification;
 
 impl<'tcx> MirPass<'tcx> for MatchBranchSimplification {
     fn run_pass(&self, tcx: TyCtxt<'tcx>, body: &mut Body<'tcx>) {
-        if tcx.sess.mir_opt_level() < 2 {
+        if tcx.sess.mir_opt_level() < 3 {
             return;
         }