diff --git a/linux-user/syscall.c b/linux-user/syscall.c
index 6056a52a55..f7cfea64bd 100644
--- a/linux-user/syscall.c
+++ b/linux-user/syscall.c
@@ -2398,7 +2398,7 @@ static void host_to_target_termios (void *dst, const void *src)
     target->c_cc[TARGET_VEOL2] = host->c_cc[VEOL2];
 }
 
-StructEntry struct_termios_def = {
+static const StructEntry struct_termios_def = {
     .convert = { host_to_target_termios, target_to_host_termios },
     .size = { sizeof(struct target_termios), sizeof(struct host_termios) },
     .align = { __alignof__(struct target_termios), __alignof__(struct host_termios) },
diff --git a/thunk.c b/thunk.c
index 7331aeb477..04f5f869c4 100644
--- a/thunk.c
+++ b/thunk.c
@@ -113,7 +113,8 @@ void thunk_register_struct(int id, const char *name, const argtype *types)
     }
 }
 
-void thunk_register_struct_direct(int id, const char *name, StructEntry *se1)
+void thunk_register_struct_direct(int id, const char *name,
+                                  const StructEntry *se1)
 {
     StructEntry *se;
     se = struct_entries + id;
diff --git a/thunk.h b/thunk.h
index d650fa4c13..017a3278bd 100644
--- a/thunk.h
+++ b/thunk.h
@@ -68,7 +68,8 @@ typedef struct bitmask_transtbl {
 } bitmask_transtbl;
 
 void thunk_register_struct(int id, const char *name, const argtype *types);
-void thunk_register_struct_direct(int id, const char *name, StructEntry *se1);
+void thunk_register_struct_direct(int id, const char *name,
+                                  const StructEntry *se1);
 const argtype *thunk_convert(void *dst, const void *src,
                              const argtype *type_ptr, int to_host);
 #ifndef NO_THUNK_TYPE_SIZE