diff --git a/mingw-w64-crt/lib32/msvcr80.def.in b/mingw-w64-crt/lib32/msvcr80.def.in
index 0981c1e..bb1ec84 100644
--- a/mingw-w64-crt/lib32/msvcr80.def.in
+++ b/mingw-w64-crt/lib32/msvcr80.def.in
@@ -541,6 +541,30 @@
 _y0
 _y1
 _yn
+_fclose_nolock
+_fflush_nolock
+_fgetwc_nolock
+_getwc_nolock == _fgetwc_nolock
+_fputwc_nolock
+_fread_nolock
+_fread_nolock_s
+_fseek_nolock
+_fseeki64_nolock
+_ftell_nolock
+_ftelli64_nolock
+_fwrite_nolock
+_getch_nolock
+_getche_nolock
+_getdcwd_nolock
+_getwch_nolock
+_getwche_nolock
+_putch_nolock
+_putwch_nolock
+_ungetc_nolock
+_ungetch_nolock
+_ungetwc_nolock
+_ungetwch_nolock
+_wgetdcwd_nolock
 abort
 abs
 acos
diff --git a/mingw-w64-crt/lib64/msvcr80.def.in b/mingw-w64-crt/lib64/msvcr80.def.in
index 5b3046f..045052e 100644
--- a/mingw-w64-crt/lib64/msvcr80.def.in
+++ b/mingw-w64-crt/lib64/msvcr80.def.in
@@ -661,6 +661,30 @@
 _y0
 _y1
 _yn
+_fclose_nolock
+_fflush_nolock
+_fgetwc_nolock
+_getwc_nolock == _fgetwc_nolock
+_fputwc_nolock
+_fread_nolock
+_fread_nolock_s
+_fseek_nolock
+_fseeki64_nolock
+_ftell_nolock
+_ftelli64_nolock
+_fwrite_nolock
+_getch_nolock
+_getche_nolock
+_getdcwd_nolock
+_getwch_nolock
+_getwche_nolock
+_putch_nolock
+_putwch_nolock
+_ungetc_nolock
+_ungetch_nolock
+_ungetwc_nolock
+_ungetwch_nolock
+_wgetdcwd_nolock
 abort
 abs
 acos