diff --git a/libc/src/__support/threads/linux/thread.cpp b/libc/src/__support/threads/linux/thread.cpp
--- a/libc/src/__support/threads/linux/thread.cpp
+++ b/libc/src/__support/threads/linux/thread.cpp
@@ -358,7 +358,7 @@
     int retval = __llvm_libc::syscall_impl(SYS_prctl, PR_GET_NAME, name_buffer);
     if (retval < 0)
       return -retval;
-    name << name_buffer;
+    name << name_buffer << cpp::StringStream::ENDS;
     return 0;
   }