diff --git a/NEWS b/NEWS
index fe87d1796cc..823cb1bde0e 100644
--- a/NEWS
+++ b/NEWS
@@ -2,6 +2,11 @@ PHP                                                                        NEWS
 |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
 ?? ??? 2021, PHP 8.0.5
 
+- Core:
+  . Changed PowerPC CPU registers used by Zend VM to work around GCC bug.
+    Old registers (r28/r29) might be clobbered by _restgpr routine used for
+    return from C function compiled with -Os. (Dmitry)
+
 - DOM:
   . Fixed bug #66783 (UAF when appending DOMDocument to element). (cmb)
 
diff --git a/Zend/zend_execute.c b/Zend/zend_execute.c
index 69b0fb5242a..2edc155e910 100644
--- a/Zend/zend_execute.c
+++ b/Zend/zend_execute.c
@@ -54,11 +54,11 @@
 #  define ZEND_VM_FP_GLOBAL_REG "%r14"
 #  define ZEND_VM_IP_GLOBAL_REG "%r15"
 # elif defined(__GNUC__) && ZEND_GCC_VERSION >= 4008 && defined(__powerpc64__)
-#  define ZEND_VM_FP_GLOBAL_REG "r28"
-#  define ZEND_VM_IP_GLOBAL_REG "r29"
+#  define ZEND_VM_FP_GLOBAL_REG "r14"
+#  define ZEND_VM_IP_GLOBAL_REG "r15"
 # elif defined(__IBMC__) && ZEND_GCC_VERSION >= 4002 && defined(__powerpc64__)
-#  define ZEND_VM_FP_GLOBAL_REG "r28"
-#  define ZEND_VM_IP_GLOBAL_REG "r29"
+#  define ZEND_VM_FP_GLOBAL_REG "r14"
+#  define ZEND_VM_IP_GLOBAL_REG "r15"
 # elif defined(__GNUC__) && ZEND_GCC_VERSION >= 4008 && defined(__aarch64__)
 #  define ZEND_VM_FP_GLOBAL_REG "x27"
 #  define ZEND_VM_IP_GLOBAL_REG "x28"