diff --git a/src/librustc_target/spec/aarch64_unknown_linux_gnu.rs b/src/librustc_target/spec/aarch64_unknown_linux_gnu.rs
index 59a285736412..b9d36c09f163 100644
--- a/src/librustc_target/spec/aarch64_unknown_linux_gnu.rs
+++ b/src/librustc_target/spec/aarch64_unknown_linux_gnu.rs
@@ -17,7 +17,7 @@ pub fn target() -> TargetResult {
         linker_flavor: LinkerFlavor::Gcc,
         options: TargetOptions {
             abi_blacklist: super::arm_base::abi_blacklist(),
-            target_mcount: "\01_mcount".to_string(),
+            target_mcount: "\u{1}_mcount".to_string(),
             .. base
         },
     })
diff --git a/src/librustc_target/spec/aarch64_unknown_linux_musl.rs b/src/librustc_target/spec/aarch64_unknown_linux_musl.rs
index 781b1322f5ac..968e82ca39fb 100644
--- a/src/librustc_target/spec/aarch64_unknown_linux_musl.rs
+++ b/src/librustc_target/spec/aarch64_unknown_linux_musl.rs
@@ -17,7 +17,7 @@ pub fn target() -> TargetResult {
         linker_flavor: LinkerFlavor::Gcc,
         options: TargetOptions {
             abi_blacklist: super::arm_base::abi_blacklist(),
-            target_mcount: "\01_mcount".to_string(),
+            target_mcount: "\u{1}_mcount".to_string(),
             .. base
         },
     })
diff --git a/src/librustc_target/spec/arm_unknown_linux_gnueabi.rs b/src/librustc_target/spec/arm_unknown_linux_gnueabi.rs
index 1173d18634e1..2f835420148f 100644
--- a/src/librustc_target/spec/arm_unknown_linux_gnueabi.rs
+++ b/src/librustc_target/spec/arm_unknown_linux_gnueabi.rs
@@ -18,7 +18,7 @@ pub fn target() -> TargetResult {
         options: TargetOptions {
             features: "+strict-align,+v6".to_string(),
             abi_blacklist: super::arm_base::abi_blacklist(),
-            target_mcount: "\01__gnu_mcount_nc".to_string(),
+            target_mcount: "\u{1}__gnu_mcount_nc".to_string(),
             .. base
         },
     })
diff --git a/src/librustc_target/spec/arm_unknown_linux_gnueabihf.rs b/src/librustc_target/spec/arm_unknown_linux_gnueabihf.rs
index 6fc7c46be3b1..cd4b2e1c9225 100644
--- a/src/librustc_target/spec/arm_unknown_linux_gnueabihf.rs
+++ b/src/librustc_target/spec/arm_unknown_linux_gnueabihf.rs
@@ -18,7 +18,7 @@ pub fn target() -> TargetResult {
         options: TargetOptions {
             features: "+strict-align,+v6,+vfp2".to_string(),
             abi_blacklist: super::arm_base::abi_blacklist(),
-            target_mcount: "\01__gnu_mcount_nc".to_string(),
+            target_mcount: "\u{1}__gnu_mcount_nc".to_string(),
             .. base
         }
     })
diff --git a/src/librustc_target/spec/arm_unknown_linux_musleabi.rs b/src/librustc_target/spec/arm_unknown_linux_musleabi.rs
index 7a2a4e85e4a1..606c3f190603 100644
--- a/src/librustc_target/spec/arm_unknown_linux_musleabi.rs
+++ b/src/librustc_target/spec/arm_unknown_linux_musleabi.rs
@@ -23,7 +23,7 @@ pub fn target() -> TargetResult {
         linker_flavor: LinkerFlavor::Gcc,
         options: TargetOptions {
             abi_blacklist: super::arm_base::abi_blacklist(),
-            target_mcount: "\01mcount".to_string(),
+            target_mcount: "\u{1}mcount".to_string(),
             .. base
         },
     })
diff --git a/src/librustc_target/spec/arm_unknown_linux_musleabihf.rs b/src/librustc_target/spec/arm_unknown_linux_musleabihf.rs
index b7aa1952cb0b..d22156bc328e 100644
--- a/src/librustc_target/spec/arm_unknown_linux_musleabihf.rs
+++ b/src/librustc_target/spec/arm_unknown_linux_musleabihf.rs
@@ -23,7 +23,7 @@ pub fn target() -> TargetResult {
         linker_flavor: LinkerFlavor::Gcc,
         options: TargetOptions {
             abi_blacklist: super::arm_base::abi_blacklist(),
-            target_mcount: "\01mcount".to_string(),
+            target_mcount: "\u{1}mcount".to_string(),
             .. base
         },
     })
diff --git a/src/librustc_target/spec/armv4t_unknown_linux_gnueabi.rs b/src/librustc_target/spec/armv4t_unknown_linux_gnueabi.rs
index 59c15f1610de..e7da24843cc0 100644
--- a/src/librustc_target/spec/armv4t_unknown_linux_gnueabi.rs
+++ b/src/librustc_target/spec/armv4t_unknown_linux_gnueabi.rs
@@ -19,7 +19,7 @@ pub fn target() -> TargetResult {
             // Atomic operations provided by compiler-builtins
             max_atomic_width: Some(32),
             abi_blacklist: super::arm_base::abi_blacklist(),
-            target_mcount: "\01__gnu_mcount_nc".to_string(),
+            target_mcount: "\u{1}__gnu_mcount_nc".to_string(),
             .. base
         }
     })
diff --git a/src/librustc_target/spec/armv5te_unknown_linux_gnueabi.rs b/src/librustc_target/spec/armv5te_unknown_linux_gnueabi.rs
index a1a61a69d052..ea586f42c269 100644
--- a/src/librustc_target/spec/armv5te_unknown_linux_gnueabi.rs
+++ b/src/librustc_target/spec/armv5te_unknown_linux_gnueabi.rs
@@ -19,7 +19,7 @@ pub fn target() -> TargetResult {
             // Atomic operations provided by compiler-builtins
             max_atomic_width: Some(32),
             abi_blacklist: super::arm_base::abi_blacklist(),
-            target_mcount: "\01__gnu_mcount_nc".to_string(),
+            target_mcount: "\u{1}__gnu_mcount_nc".to_string(),
             .. base
         }
     })
diff --git a/src/librustc_target/spec/armv5te_unknown_linux_musleabi.rs b/src/librustc_target/spec/armv5te_unknown_linux_musleabi.rs
index 9b44a54715e7..dae5c8c3d750 100644
--- a/src/librustc_target/spec/armv5te_unknown_linux_musleabi.rs
+++ b/src/librustc_target/spec/armv5te_unknown_linux_musleabi.rs
@@ -22,7 +22,7 @@ pub fn target() -> TargetResult {
             // Atomic operations provided by compiler-builtins
             max_atomic_width: Some(32),
             abi_blacklist: super::arm_base::abi_blacklist(),
-            target_mcount: "\01mcount".to_string(),
+            target_mcount: "\u{1}mcount".to_string(),
             .. base
         }
     })
diff --git a/src/librustc_target/spec/armv6_unknown_freebsd.rs b/src/librustc_target/spec/armv6_unknown_freebsd.rs
index e706c8281d23..a90590a39e75 100644
--- a/src/librustc_target/spec/armv6_unknown_freebsd.rs
+++ b/src/librustc_target/spec/armv6_unknown_freebsd.rs
@@ -18,7 +18,7 @@ pub fn target() -> TargetResult {
             features: "+v6,+vfp2".to_string(),
             max_atomic_width: Some(64),
             abi_blacklist: super::arm_base::abi_blacklist(),
-            target_mcount: "\01__gnu_mcount_nc".to_string(),
+            target_mcount: "\u{1}__gnu_mcount_nc".to_string(),
             .. base
         }
     })
diff --git a/src/librustc_target/spec/armv7_unknown_cloudabi_eabihf.rs b/src/librustc_target/spec/armv7_unknown_cloudabi_eabihf.rs
index 70d4985ab860..c03f4b544ed0 100644
--- a/src/librustc_target/spec/armv7_unknown_cloudabi_eabihf.rs
+++ b/src/librustc_target/spec/armv7_unknown_cloudabi_eabihf.rs
@@ -20,7 +20,7 @@ pub fn target() -> TargetResult {
         target_vendor: "unknown".to_string(),
         linker_flavor: LinkerFlavor::Gcc,
         options: TargetOptions {
-            target_mcount: "\01mcount".to_string(),
+            target_mcount: "\u{1}mcount".to_string(),
             .. base
         },
     })
diff --git a/src/librustc_target/spec/armv7_unknown_freebsd.rs b/src/librustc_target/spec/armv7_unknown_freebsd.rs
index 0f9ee5d44a95..ca7ab474bef8 100644
--- a/src/librustc_target/spec/armv7_unknown_freebsd.rs
+++ b/src/librustc_target/spec/armv7_unknown_freebsd.rs
@@ -18,7 +18,7 @@ pub fn target() -> TargetResult {
             features: "+v7,+vfp3,+d16,+thumb2,-neon".to_string(),
             max_atomic_width: Some(64),
             abi_blacklist: super::arm_base::abi_blacklist(),
-            target_mcount: "\01__gnu_mcount_nc".to_string(),
+            target_mcount: "\u{1}__gnu_mcount_nc".to_string(),
             .. base
         }
     })
diff --git a/src/librustc_target/spec/armv7_unknown_linux_gnueabihf.rs b/src/librustc_target/spec/armv7_unknown_linux_gnueabihf.rs
index afba6f608ee0..f0952cccb208 100644
--- a/src/librustc_target/spec/armv7_unknown_linux_gnueabihf.rs
+++ b/src/librustc_target/spec/armv7_unknown_linux_gnueabihf.rs
@@ -23,7 +23,7 @@ pub fn target() -> TargetResult {
             cpu: "generic".to_string(),
             max_atomic_width: Some(64),
             abi_blacklist: super::arm_base::abi_blacklist(),
-            target_mcount: "\01__gnu_mcount_nc".to_string(),
+            target_mcount: "\u{1}__gnu_mcount_nc".to_string(),
             .. base
         }
     })
diff --git a/src/librustc_target/spec/armv7_unknown_linux_musleabihf.rs b/src/librustc_target/spec/armv7_unknown_linux_musleabihf.rs
index 516d0401adf5..a9974f6b80c9 100644
--- a/src/librustc_target/spec/armv7_unknown_linux_musleabihf.rs
+++ b/src/librustc_target/spec/armv7_unknown_linux_musleabihf.rs
@@ -26,7 +26,7 @@ pub fn target() -> TargetResult {
             cpu: "generic".to_string(),
             max_atomic_width: Some(64),
             abi_blacklist: super::arm_base::abi_blacklist(),
-            target_mcount: "\01mcount".to_string(),
+            target_mcount: "\u{1}mcount".to_string(),
             .. base
         }
     })
diff --git a/src/librustc_target/spec/i686_apple_darwin.rs b/src/librustc_target/spec/i686_apple_darwin.rs
index a82ff33ce1db..58c59cc87284 100644
--- a/src/librustc_target/spec/i686_apple_darwin.rs
+++ b/src/librustc_target/spec/i686_apple_darwin.rs
@@ -20,7 +20,7 @@ pub fn target() -> TargetResult {
         target_vendor: "apple".to_string(),
         linker_flavor: LinkerFlavor::Gcc,
         options: TargetOptions {
-            target_mcount: "\01mcount".to_string(),
+            target_mcount: "\u{1}mcount".to_string(),
             .. base
         },
     })
diff --git a/src/librustc_target/spec/x86_64_apple_darwin.rs b/src/librustc_target/spec/x86_64_apple_darwin.rs
index fecc20c01c5e..c54181741b3c 100644
--- a/src/librustc_target/spec/x86_64_apple_darwin.rs
+++ b/src/librustc_target/spec/x86_64_apple_darwin.rs
@@ -20,7 +20,7 @@ pub fn target() -> TargetResult {
         target_vendor: "apple".to_string(),
         linker_flavor: LinkerFlavor::Gcc,
         options: TargetOptions {
-            target_mcount: "\01mcount".to_string(),
+            target_mcount: "\u{1}mcount".to_string(),
             .. base
         },
     })