diff --git a/INSTALL b/INSTALL
index 717b34a374..7e8dcbb089 100644
--- a/INSTALL
+++ b/INSTALL
@@ -559,6 +559,10 @@ build the GNU C Library:
      version 5.3.0 is the newest verified to work to build the GNU C
      Library.
 
+     Testing the GNU C Library requires 'gawk' to be compiled with
+     support for high precision arithmetic via the 'MPFR'
+     multiple-precision floating-point computation library.
+
    * GNU 'bison' 2.7 or later
 
      'bison' is used to generate the 'yacc' parser code in the 'intl'
diff --git a/NEWS b/NEWS
index ee42601551..4cb307fd02 100644
--- a/NEWS
+++ b/NEWS
@@ -79,6 +79,9 @@ Changes to build and runtime requirements:
   act as a "shall occur" cancellation point, in which case it might
   not issue a syscall or trigger a deferred cancellation event.
 
+* Testing the GNU C Library requires GNU awk to be compiled with support for
+  high precision arithmetic via the MPFR library.
+
 Security related changes:
 
 The following CVEs were fixed in this release, details of which can be
diff --git a/manual/install.texi b/manual/install.texi
index 05a774b33b..b5292a976a 100644
--- a/manual/install.texi
+++ b/manual/install.texi
@@ -602,6 +602,10 @@ function, which was introduced in version 3.1.2 of @code{gawk}.
 As of release time, @code{gawk} version 5.3.0 is the newest verified
 to work to build @theglibc{}.
 
+Testing the GNU C Library requires @code{gawk} to be compiled with
+support for high precision arithmetic via the @code{MPFR}
+multiple-precision floating-point computation library.
+
 @item
 GNU @code{bison} 2.7 or later