diff --git a/ChangeLog b/ChangeLog
index 5320c67..cefbe03 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+2020-06-15  Jessica Clarke <jrtc27@jrtc27.com>
+
+	* config.guess (x86_64:Linux:*:*): Detect x32 ABI. This is
+	currently only supported when CC_FOR_BUILD is available, as that
+	ultimately governs what the native ABI is.
+
 2020-05-04  Emery Hemingway  <ehmry@posteo.net>
 
 	* config.sub (-genode*): New.
diff --git a/config.guess b/config.guess
index 11fda52..92bfc33 100755
--- a/config.guess
+++ b/config.guess
@@ -1095,7 +1095,17 @@ EOF
 	echo "$UNAME_MACHINE"-dec-linux-"$LIBC"
 	exit ;;
     x86_64:Linux:*:*)
-	echo "$UNAME_MACHINE"-pc-linux-"$LIBC"
+	set_cc_for_build
+	LIBCABI=$LIBC
+	if [ "$CC_FOR_BUILD" != no_compiler_found ]; then
+	    if (echo '#ifdef __ILP32__'; echo IS_X32; echo '#endif') | \
+		(CCOPTS="" $CC_FOR_BUILD -E - 2>/dev/null) | \
+		grep IS_X32 >/dev/null
+	    then
+		LIBCABI="$LIBC"x32
+	    fi
+	fi
+	echo "$UNAME_MACHINE"-pc-linux-"$LIBCABI"
 	exit ;;
     xtensa*:Linux:*:*)
 	echo "$UNAME_MACHINE"-unknown-linux-"$LIBC"