diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index a56fc5b05fa..d90cb6d90e4 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,8 @@
+2020-09-16  Simon Marchi  <simon.marchi@efficios.com>
+
+	* gdb-gdb.py.in (class StructTypePrettyPrinter) <to_string>:
+	Change instance_flags to m_instance_flags.
+
 2020-09-16  Tom Tromey  <tromey@adacore.com>
 
 	PR gdb/26598:
diff --git a/gdb/gdb-gdb.py.in b/gdb/gdb-gdb.py.in
index 594592d4d16..6594ac10b85 100644
--- a/gdb/gdb-gdb.py.in
+++ b/gdb/gdb-gdb.py.in
@@ -113,7 +113,7 @@ class StructTypePrettyPrinter:
         fields.append("reference_type = %s" % self.val['reference_type'])
         fields.append("chain = %s" % self.val['reference_type'])
         fields.append("instance_flags = %s"
-                      % TypeFlagsPrinter(self.val['instance_flags']))
+                      % TypeFlagsPrinter(self.val['m_instance_flags']))
         fields.append("length = %d" % self.val['length'])
         fields.append("main_type = %s" % self.val['main_type'])
         return "\n{" + ",\n ".join(fields) + "}"