diff --git a/m4/jm-macros.m4 b/m4/jm-macros.m4
index b55de11da..454472ec8 100644
--- a/m4/jm-macros.m4
+++ b/m4/jm-macros.m4
@@ -188,7 +188,7 @@ AC_DEFUN(jm_MACROS,
   test $am_cv_func_strtod_needs_libm = yes && POW_LIBM=-lm
 
   jm_LANGINFO_CODESET
-
+  jm_GLIBC21
   jm_ICONV
 
   # These tests are for df.