diff --git a/src/librustc_back/target/x86_64_rumprun_netbsd.rs b/src/librustc_back/target/x86_64_rumprun_netbsd.rs
index af5d21c4d93e4..a55aaf9699c8b 100644
--- a/src/librustc_back/target/x86_64_rumprun_netbsd.rs
+++ b/src/librustc_back/target/x86_64_rumprun_netbsd.rs
@@ -12,6 +12,7 @@ use target::Target;
 
 pub fn target() -> Target {
     let mut base = super::netbsd_base::opts();
+    base.cpu = "x86-64".to_string();
     base.pre_link_args.push("-m64".to_string());
     base.linker = "x86_64-rumprun-netbsd-gcc".to_string();
     base.ar = "x86_64-rumprun-netbsd-ar".to_string();
diff --git a/src/librustc_back/target/x86_64_unknown_bitrig.rs b/src/librustc_back/target/x86_64_unknown_bitrig.rs
index 87753da540a36..2761782d46e71 100644
--- a/src/librustc_back/target/x86_64_unknown_bitrig.rs
+++ b/src/librustc_back/target/x86_64_unknown_bitrig.rs
@@ -12,6 +12,7 @@ use target::Target;
 
 pub fn target() -> Target {
     let mut base = super::bitrig_base::opts();
+    base.cpu = "x86-64".to_string();
     base.max_atomic_width = 64;
     base.pre_link_args.push("-m64".to_string());
 
diff --git a/src/librustc_back/target/x86_64_unknown_netbsd.rs b/src/librustc_back/target/x86_64_unknown_netbsd.rs
index 7e6d1b78469e2..6dc744cdf99df 100644
--- a/src/librustc_back/target/x86_64_unknown_netbsd.rs
+++ b/src/librustc_back/target/x86_64_unknown_netbsd.rs
@@ -12,6 +12,7 @@ use target::Target;
 
 pub fn target() -> Target {
     let mut base = super::netbsd_base::opts();
+    base.cpu = "x86-64".to_string();
     base.max_atomic_width = 64;
     base.pre_link_args.push("-m64".to_string());