diff --git a/config/c-compiler.m4 b/config/c-compiler.m4
index b35436481c..076656c77f 100644
--- a/config/c-compiler.m4
+++ b/config/c-compiler.m4
@@ -310,18 +310,19 @@ fi])# PGAC_C_BUILTIN_CONSTANT_P
 # and define HAVE__BUILTIN_OP_OVERFLOW if so.
 #
 # Check for the most complicated case, 64 bit multiplication, as a
-# proxy for all of the operations. Use volatile variables to avoid the
-# compiler computing result at compile time, even though the runtime
-# might not supply operation. Have to link to be sure to recognize a
-# missing __builtin_mul_overflow.
+# proxy for all of the operations.  To detect the case where the compiler
+# knows the function but library support is missing, we must link not just
+# compile, and store the results in global variables so the compiler doesn't
+# optimize away the call.
 AC_DEFUN([PGAC_C_BUILTIN_OP_OVERFLOW],
 [AC_CACHE_CHECK(for __builtin_mul_overflow, pgac_cv__builtin_op_overflow,
-[AC_LINK_IFELSE([AC_LANG_PROGRAM([],
-[PG_INT64_TYPE a = 1;
+[AC_LINK_IFELSE([AC_LANG_PROGRAM([
+PG_INT64_TYPE a = 1;
 PG_INT64_TYPE b = 1;
 PG_INT64_TYPE result;
-__builtin_mul_overflow(*(volatile PG_INT64_TYPE *) a, *(volatile PG_INT64_TYPE *) b, &result);]
-)],
+int oflo;
+],
+[oflo = __builtin_mul_overflow(a, b, &result);])],
 [pgac_cv__builtin_op_overflow=yes],
 [pgac_cv__builtin_op_overflow=no])])
 if test x"$pgac_cv__builtin_op_overflow" = xyes ; then
diff --git a/configure b/configure
index 22ca4230fc..d9b7b8d7ec 100755
--- a/configure
+++ b/configure
@@ -14485,14 +14485,15 @@ else
   cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
 
-int
-main ()
-{
 PG_INT64_TYPE a = 1;
 PG_INT64_TYPE b = 1;
 PG_INT64_TYPE result;
-__builtin_mul_overflow(*(volatile PG_INT64_TYPE *) a, *(volatile PG_INT64_TYPE *) b, &result);
+int oflo;
 
+int
+main ()
+{
+oflo = __builtin_mul_overflow(a, b, &result);
   ;
   return 0;
 }