diff --git a/build_system/build_sysroot.rs b/build_system/build_sysroot.rs
index 6a4d6aaa356..62a025b4f8f 100644
--- a/build_system/build_sysroot.rs
+++ b/build_system/build_sysroot.rs
@@ -240,7 +240,8 @@ fn build_clif_sysroot_for_triple(
     rustflags
         .push_str(&format!(" --sysroot={}", RTSTARTUP_SYSROOT.to_path(dirs).to_str().unwrap()));
     if channel == "release" {
-        rustflags.push_str(" -Zmir-opt-level=3");
+        // FIXME re-enable DataflowConstProp once rust-lang/rust#108166 is fixed
+        rustflags.push_str(" -Zmir-opt-level=3 -Zmir-enable-passes=-DataflowConstProp");
     }
     compiler.rustflags += &rustflags;
     let mut build_cmd = STANDARD_LIBRARY.build(&compiler, dirs);
diff --git a/rust-toolchain b/rust-toolchain
index eae1c2f9298..02cddbac1d9 100644
--- a/rust-toolchain
+++ b/rust-toolchain
@@ -1,3 +1,3 @@
 [toolchain]
-channel = "nightly-2023-02-15"
+channel = "nightly-2023-02-16"
 components = ["rust-src", "rustc-dev", "llvm-tools-preview"]