2 files changed, 27 insertions, 3 deletions
diff --git a/src/grt/grt-cbinding.c b/src/grt/grt-cbinding.c
index b95c0f0..1083d58 100644
--- a/src/grt/grt-cbinding.c
+++ b/src/grt/grt-cbinding.c
@@ -70,6 +70,30 @@ __ghdl_fprintf_clock (FILE *stream, int a, int b)
   fprintf (stream, "%3d.%03d", a, b);
 }
 
+#ifndef getc_unlocked
+int
+getc_unlocked (FILE *stream)
+{
+  return getc (stream);
+}
+#endif
+
+#ifndef putc_unlocked
+int
+putc_unlocked (int c, FILE *stream)
+{
+  return putc (c, stream);
+}
+#endif
+
+#ifndef feof_unlocked
+int
+feof_unlocked (FILE *stream)
+{
+  return feof (stream);
+}
+#endif
+
 #ifndef WITH_GNAT_RUN_TIME
 void
 __gnat_last_chance_handler (void)
diff --git a/src/grt/grt-stdio.ads b/src/grt/grt-stdio.ads
index 990fc74..9084eab 100644
--- a/src/grt/grt-stdio.ads
+++ b/src/grt/grt-stdio.ads
@@ -86,14 +86,14 @@ private
    pragma Import (C, fread);
 
    pragma Import (C, fputs);
-   pragma Import (C, fputc);
+   pragma Import (C, fputc, "putc_unlocked");
 
-   pragma Import (C, fgetc);
+   pragma Import (C, fgetc, "getc_unlocked");
    pragma Import (C, fgets);
    pragma Import (C, ungetc);
 
    pragma Import (C, fflush);
-   pragma Import (C, feof);
+   pragma Import (C, feof, "feof_unlocked");
    pragma Import (C, ftell);
    pragma Import (C, fclose);