diff --git a/doc/langref.html.in b/doc/langref.html.in
index 36711e555a..5d087f72a2 100644
--- a/doc/langref.html.in
+++ b/doc/langref.html.in
@@ -9604,7 +9604,7 @@ pub fn build(b: *std.Build) void {
       {#header_close#}
 
       {#header_open|Single Threaded Builds#}
-      <p>Zig has a compile option <kbd>--single-threaded</kbd> which has the following effects:</p>
+      <p>Zig has a compile option <kbd>-fsingle-threaded</kbd> which has the following effects:</p>
       <ul>
         <li>All {#link|Thread Local Variables#} are treated as regular {#link|Container Level Variables#}.</li>
         <li>The overhead of {#link|Async Functions#} becomes equivalent to function call overhead.</li>
diff --git a/tools/update_cpu_features.zig b/tools/update_cpu_features.zig
index 647d2c5a9b..ee92d63227 100644
--- a/tools/update_cpu_features.zig
+++ b/tools/update_cpu_features.zig
@@ -1306,7 +1306,7 @@ fn usageAndExit(file: fs.File, arg0: []const u8, code: u8) noreturn {
         \\
         \\Updates lib/std/target/<target>.zig from llvm/lib/Target/<Target>/<Target>.td .
         \\
-        \\On a less beefy system, or when debugging, compile with --single-threaded.
+        \\On a less beefy system, or when debugging, compile with -fsingle-threaded.
         \\
     , .{arg0}) catch std.process.exit(1);
     std.process.exit(code);