diff --git a/gcc/ginclude/float.h b/gcc/ginclude/float.h
index 83c5ad55a53..39139ee8dd1 100644
--- a/gcc/ginclude/float.h
+++ b/gcc/ginclude/float.h
@@ -285,7 +285,8 @@ see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
 
 #endif /* C2X */
 
-#ifdef __STDC_WANT_IEC_60559_BFP_EXT__
+#if (defined __STDC_WANT_IEC_60559_BFP_EXT__ \
+     || defined __STDC_WANT_IEC_60559_EXT__)
 /* Number of decimal digits for which conversions between decimal
    character strings and binary formats, in both directions, are
    correctly rounded.  */
diff --git a/gcc/testsuite/gcc.dg/cr-decimal-dig-3.c b/gcc/testsuite/gcc.dg/cr-decimal-dig-3.c
new file mode 100644
index 00000000000..8e07b67dd52
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/cr-decimal-dig-3.c
@@ -0,0 +1,14 @@
+/* Test C2x CR_DECIMAL_DIG: defined for __STDC_WANT_IEC_60559_EXT__.  */
+/* { dg-do compile } */
+/* { dg-options "-std=c2x" } */
+
+#define __STDC_WANT_IEC_60559_EXT__
+#include <float.h>
+
+#ifndef CR_DECIMAL_DIG
+#error "CR_DECIMAL_DIG not defined"
+#endif
+
+#if CR_DECIMAL_DIG < DECIMAL_DIG + 3
+#error "CR_DECIMAL_DIG too small"
+#endif