diff --git a/config/c-compiler.m4 b/config/c-compiler.m4
index 8e76a455a3..a27057d2c3 100644
--- a/config/c-compiler.m4
+++ b/config/c-compiler.m4
@@ -492,7 +492,7 @@ AC_DEFUN([PGAC_HAVE_GCC__ATOMIC_INT64_CAS],
   [pgac_cv_gcc_atomic_int64_cas="yes"],
   [pgac_cv_gcc_atomic_int64_cas="no"])])
 if test x"$pgac_cv_gcc_atomic_int64_cas" = x"yes"; then
-  AC_DEFINE(HAVE_GCC__ATOMIC_INT64_CAS, 1, [Define to 1 if you have __atomic_compare_exchange_n(int64 *, int *, int64).])
+  AC_DEFINE(HAVE_GCC__ATOMIC_INT64_CAS, 1, [Define to 1 if you have __atomic_compare_exchange_n(int64 *, int64 *, int64).])
 fi])# PGAC_HAVE_GCC__ATOMIC_INT64_CAS
 
 # PGAC_SSE42_CRC32_INTRINSICS
diff --git a/src/include/pg_config.h.in b/src/include/pg_config.h.in
index 68f5562533..76fec32a7e 100644
--- a/src/include/pg_config.h.in
+++ b/src/include/pg_config.h.in
@@ -202,8 +202,8 @@
 /* Define to 1 if you have __atomic_compare_exchange_n(int *, int *, int). */
 #undef HAVE_GCC__ATOMIC_INT32_CAS
 
-/* Define to 1 if you have __atomic_compare_exchange_n(int64 *, int *, int64).
-   */
+/* Define to 1 if you have __atomic_compare_exchange_n(int64 *, int64 *,
+   int64). */
 #undef HAVE_GCC__ATOMIC_INT64_CAS
 
 /* Define to 1 if you have __sync_lock_test_and_set(char *) and friends. */