diff --git a/opcodes/ChangeLog b/opcodes/ChangeLog
index 6e7b8f4c3e1..4c1e08d0ceb 100644
--- a/opcodes/ChangeLog
+++ b/opcodes/ChangeLog
@@ -1,3 +1,9 @@
+2020-08-29  Alan Modra  <amodra@gmail.com>
+
+	PR 26446
+	* csky-opc.h (MAX_OPRND_NUM): Define to 5.
+	(union csky_operand): Use MAX_OPRND_NUM to size oprnds array.
+
 2020-08-28  Alan Modra  <amodra@gmail.com>
 
 	PR 26449
diff --git a/opcodes/csky-opc.h b/opcodes/csky-opc.h
index 95df44dad38..0a0b138fac7 100644
--- a/opcodes/csky-opc.h
+++ b/opcodes/csky-opc.h
@@ -22,7 +22,7 @@
 #include "opcode/csky.h"
 
 #define OP_TABLE_NUM    2
-#define MAX_OPRND_NUM   4
+#define MAX_OPRND_NUM   5
 
 enum operand_type
 {
@@ -222,7 +222,7 @@ struct soperand
 
 union csky_operand
 {
-  struct operand oprnds[5];
+  struct operand oprnds[MAX_OPRND_NUM];
   struct suboperand1
   {
     struct operand oprnd;