diff --git a/platform/switch_ppc_aix.h b/platform/switch_ppc_aix.h
index 45a277ab..c7d476f6 100644
--- a/platform/switch_ppc_aix.h
+++ b/platform/switch_ppc_aix.h
@@ -56,14 +56,14 @@ slp_switch(void)
     register int err;
     register int *stackref, stsizediff;
     __asm__ volatile ("" : : : REGS_TO_SAVE);
-    __asm__ ("mr %0, 1" : "=g" (stackref) : );
+    __asm__ ("mr %0, 1" : "=r" (stackref) : );
     {
         SLP_SAVE_STATE(stackref, stsizediff);
         __asm__ volatile (
             "mr 11, %0\n"
             "add 1, 1, 11\n"
             : /* no outputs */
-            : "g" (stsizediff)
+            : "r" (stsizediff)
             : "11"
             );
         SLP_RESTORE_STATE();