diff --git a/src/perl-mmagic-xs.c b/src/perl-mmagic-xs.c
index 92054f3..b84bf75 100644
--- a/src/perl-mmagic-xs.c
+++ b/src/perl-mmagic-xs.c
@@ -1110,7 +1110,7 @@ fmm_parse_magic_line(PerlFMM *state, char *l, int lineno)
 
  error:
     FMM_SET_ERROR(state, err);
-    croak(SvPV_nolen(err));
+    croak("%s", SvPV_nolen(err));
 }
 
 /* maps to mod_mime_magic::apprentice */