diff --git a/rust-version b/rust-version
index 38c99cc0b53..8e4cdeddfcc 100644
--- a/rust-version
+++ b/rust-version
@@ -1 +1 @@
-297a8018b525c28ef10ee6a91d61954839b508b9
+6af09d2505f38e4f1df291df56d497fb2ad935ed
diff --git a/src/helpers.rs b/src/helpers.rs
index 3ffb983aa69..7a63bb03dfe 100644
--- a/src/helpers.rs
+++ b/src/helpers.rs
@@ -510,7 +510,7 @@ fn set_last_error_from_io_error(&mut self, err_kind: std::io::ErrorKind) -> Inte
         let this = self.eval_context_mut();
         let target = &this.tcx.sess.target;
         let target_os = &target.os;
-        let last_error = if target.families.contains(&"unix".to_owned()) {
+        let last_error = if target.families.iter().any(|f| f == "unix") {
             this.eval_libc(match err_kind {
                 ConnectionRefused => "ECONNREFUSED",
                 ConnectionReset => "ECONNRESET",
@@ -534,7 +534,7 @@ fn set_last_error_from_io_error(&mut self, err_kind: std::io::ErrorKind) -> Inte
                     )
                 }
             })?
-        } else if target.families.contains(&"windows".to_owned()) {
+        } else if target.families.iter().any(|f| f == "windows") {
             // FIXME: we have to finish implementing the Windows equivalent of this.
             this.eval_windows(
                 "c",
diff --git a/src/machine.rs b/src/machine.rs
index e9ed5072442..b4b07a61a8b 100644
--- a/src/machine.rs
+++ b/src/machine.rs
@@ -227,7 +227,7 @@ fn add_extern_static<'tcx, 'mir>(
     pub fn init_extern_statics<'tcx, 'mir>(
         this: &mut MiriEvalContext<'mir, 'tcx>,
     ) -> InterpResult<'tcx> {
-        match this.tcx.sess.target.os.as_str() {
+        match this.tcx.sess.target.os.as_ref() {
             "linux" => {
                 // "environ"
                 Self::add_extern_static(
diff --git a/src/shims/env.rs b/src/shims/env.rs
index c2050647abc..822bef56ce6 100644
--- a/src/shims/env.rs
+++ b/src/shims/env.rs
@@ -41,7 +41,7 @@ pub(crate) fn init<'mir>(
         mut excluded_env_vars: Vec<String>,
         forwarded_env_vars: Vec<String>,
     ) -> InterpResult<'tcx> {
-        let target_os = ecx.tcx.sess.target.os.as_str();
+        let target_os = ecx.tcx.sess.target.os.as_ref();
         // HACK: Exclude `TERM` var to avoid terminfo trying to open the termcap file.
         // This is (a) very slow and (b) does not work on Windows.
         excluded_env_vars.push("TERM".to_owned());
diff --git a/src/shims/foreign_items.rs b/src/shims/foreign_items.rs
index ecffd310de5..d9e4d938224 100644
--- a/src/shims/foreign_items.rs
+++ b/src/shims/foreign_items.rs
@@ -46,7 +46,7 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriEvalContextExt<'mir, 'tcx
     fn min_align(&self, size: u64, kind: MiriMemoryKind) -> Align {
         let this = self.eval_context_ref();
         // List taken from `libstd/sys_common/alloc.rs`.
-        let min_align = match this.tcx.sess.target.arch.as_str() {
+        let min_align = match this.tcx.sess.target.arch.as_ref() {
             "x86" | "arm" | "mips" | "powerpc" | "powerpc64" | "asmjs" | "wasm32" => 8,
             "x86_64" | "aarch64" | "mips64" | "s390x" | "sparc64" => 16,
             arch => bug!("Unsupported target architecture: {}", arch),
@@ -695,7 +695,7 @@ fn emulate_foreign_item_by_name(
             }
 
             // Platform-specific shims
-            _ => match this.tcx.sess.target.os.as_str() {
+            _ => match this.tcx.sess.target.os.as_ref() {
                 "linux" | "macos" => return shims::posix::foreign_items::EvalContextExt::emulate_foreign_item_by_name(this, link_name, abi, args, dest, ret),
                 "windows" => return shims::windows::foreign_items::EvalContextExt::emulate_foreign_item_by_name(this, link_name, abi, args, dest, ret),
                 target => throw_unsup_format!("the target `{}` is not supported", target),
diff --git a/src/shims/posix/foreign_items.rs b/src/shims/posix/foreign_items.rs
index 02fb7089c34..36bf5305992 100644
--- a/src/shims/posix/foreign_items.rs
+++ b/src/shims/posix/foreign_items.rs
@@ -462,7 +462,7 @@ fn emulate_foreign_item_by_name(
 
             // Platform-specific shims
             _ => {
-                match this.tcx.sess.target.os.as_str() {
+                match this.tcx.sess.target.os.as_ref() {
                     "linux" => return shims::posix::linux::foreign_items::EvalContextExt::emulate_foreign_item_by_name(this, link_name, abi, args, dest, ret),
                     "macos" => return shims::posix::macos::foreign_items::EvalContextExt::emulate_foreign_item_by_name(this, link_name, abi, args, dest, ret),
                     _ => unreachable!(),