diff --git a/configure.ac b/configure.ac
index 1d79597..f9c3c30 100644
--- a/configure.ac
+++ b/configure.ac
@@ -301,6 +301,19 @@
 
 AC_CHECK_SIZEOF(long)
 
+# On aarch64 before glibc 2.20 we would get the kernel user_pt_regs instead
+# of the user_regs_struct from sys/user.h. They are structurally the same
+# but we get either one or the other.
+AC_CHECK_TYPE([struct user_regs_struct],
+              [sys_user_has_user_regs=yes], [sys_user_has_user_regs=no],
+              [[#include <sys/ptrace.h>]
+               [#include <sys/time.h>]
+               [#include <sys/user.h>]])
+if test "$sys_user_has_user_regs" = "yes"; then
+  AC_DEFINE(HAVE_SYS_USER_REGS, 1,
+            [Define to 1 if <sys/user.h> defines struct user_regs_struct])
+fi
+
 # On a 64-bit host where can can use $CC -m32, we'll run two sets of tests.
 # Likewise in a 32-bit build on a host where $CC -m64 works.
 utrace_BIARCH