diff --git a/src/auto/configure b/src/auto/configure
index bbfaafc..9d76f89 100755
--- a/src/auto/configure
+++ b/src/auto/configure
@@ -4510,9 +4510,9 @@
   CLANG_VERSION=`expr $CLANG_MAJOR '*' 1000000 '+' $CLANG_MINOR '*' 1000 '+' $CLANG_REVISION`
   { $as_echo "$as_me:${as_lineno-$LINENO}: result: $CLANG_VERSION" >&5
 $as_echo "$CLANG_VERSION" >&6; }
-          { $as_echo "$as_me:${as_lineno-$LINENO}: checking if clang supports -fno-strength-reduce" >&5
+            { $as_echo "$as_me:${as_lineno-$LINENO}: checking if clang supports -fno-strength-reduce" >&5
 $as_echo_n "checking if clang supports -fno-strength-reduce... " >&6; }
-  if test "$CLANG_VERSION" -ge 500002075 ; then
+  if test "$CLANG_MAJOR" -ge 10 -o "$CLANG_VERSION" -ge 500002075 ; then
     { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
 $as_echo "no" >&6; }
     CFLAGS=`echo "$CFLAGS" | sed -e 's/-fno-strength-reduce/ /'`
diff --git a/src/configure.ac b/src/configure.ac
index fe2a401..e511b35 100644
--- a/src/configure.ac
+++ b/src/configure.ac
@@ -127,8 +127,9 @@
   dnl change the constant 500002075 below appropriately.  To get the
   dnl integer corresponding to a version number, refer to the
   dnl definition of CLANG_VERSION above.
+  dnl Clang 11 reports "11", assume Clang 10 and later work like this.
   AC_MSG_CHECKING(if clang supports -fno-strength-reduce)
-  if test "$CLANG_VERSION" -ge 500002075 ; then
+  if test "$CLANG_MAJOR" -ge 10 -o "$CLANG_VERSION" -ge 500002075 ; then
     AC_MSG_RESULT(no)
     CFLAGS=`echo "$CFLAGS" | sed -e 's/-fno-strength-reduce/ /'`
   else
diff --git a/src/version.c b/src/version.c
index 56a0797..6854c10 100644
--- a/src/version.c
+++ b/src/version.c
@@ -751,6 +751,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    2431,
+/**/
     2430,
 /**/
     2429,