Index: libphobos/libdruntime/core/sys/posix/ucontext.d
--- libphobos/libdruntime/core/sys/posix/ucontext.d.orig
+++ libphobos/libdruntime/core/sys/posix/ucontext.d
@@ -1381,6 +1381,25 @@ else version (OpenBSD)
             trapframe sc_frame;
         }
     }
+    else version (PPC64)
+    {
+        struct sigcontext
+        {
+            c_long       sc_cookie;
+            int          sc_mask;
+            c_long[32]   sc_reg;
+            c_long       sc_lr;
+            c_long       sc_cr;
+            c_long       sc_xer;
+            c_long       sc_ctr;
+            c_long       sc_pc;
+            c_long       sc_ps;
+            c_long       sc_vrsave;
+            ulong[2][64] sc_vsx; // __uint128_t
+            ulong        sc_fpscr;
+            ulong        sc_vcsr;
+        }
+    }
     else version (SPARC64)
     {
         struct sigcontext
