diff --git a/configure.in b/configure.in
index 618f9d4579..1d28f0f982 100644
--- a/configure.in
+++ b/configure.in
@@ -2037,11 +2037,11 @@ if test x"$USE_SSE42_CRC32C" = x"1"; then
   AC_MSG_RESULT(SSE 4.2)
 else
   if test x"$USE_SSE42_CRC32C_WITH_RUNTIME_CHECK" = x"1"; then
-    AC_DEFINE(USE_SSE42_CRC32C_WITH_RUNTIME_CHECK, 1, [Define to 1 to use Intel SSSE 4.2 CRC instructions with a runtime check.])
+    AC_DEFINE(USE_SSE42_CRC32C_WITH_RUNTIME_CHECK, 1, [Define to 1 to use Intel SSE 4.2 CRC instructions with a runtime check.])
     PG_CRC32C_OBJS="pg_crc32c_sse42.o pg_crc32c_sb8.o pg_crc32c_choose.o"
     AC_MSG_RESULT(SSE 4.2 with runtime check)
   else
-    AC_DEFINE(USE_SLICING_BY_8_CRC32C, 1, [Define to 1 to use Intel SSE 4.2 CRC instructions with a runtime check.])
+    AC_DEFINE(USE_SLICING_BY_8_CRC32C, 1, [Define to 1 to use software CRC-32C implementation (slicing-by-8).])
     PG_CRC32C_OBJS="pg_crc32c_sb8.o"
     AC_MSG_RESULT(slicing-by-8)
   fi
diff --git a/src/include/pg_config.h.in b/src/include/pg_config.h.in
index 625cd21ed3..eb4b43fed0 100644
--- a/src/include/pg_config.h.in
+++ b/src/include/pg_config.h.in
@@ -893,13 +893,13 @@
 /* Use replacement snprintf() functions. */
 #undef USE_REPL_SNPRINTF
 
-/* Define to 1 to use Intel SSE 4.2 CRC instructions with a runtime check. */
+/* Define to 1 to use software CRC-32C implementation (slicing-by-8). */
 #undef USE_SLICING_BY_8_CRC32C
 
 /* Define to 1 use Intel SSE 4.2 CRC instructions. */
 #undef USE_SSE42_CRC32C
 
-/* Define to 1 to use Intel SSSE 4.2 CRC instructions with a runtime check. */
+/* Define to 1 to use Intel SSE 4.2 CRC instructions with a runtime check. */
 #undef USE_SSE42_CRC32C_WITH_RUNTIME_CHECK
 
 /* Define to build with systemd support. (--with-systemd) */