diff --git a/src/backend/postmaster/syslogger.c b/src/backend/postmaster/syslogger.c
index 5434826..77772be 100644
--- a/src/backend/postmaster/syslogger.c
+++ b/src/backend/postmaster/syslogger.c
@@ -45,6 +45,7 @@
 #include "storage/latch.h"
 #include "storage/pg_shmem.h"
 #include "utils/guc.h"
+#include "utils/guc_values.h"
 #include "utils/ps_status.h"
 #include "utils/timestamp.h"
 
@@ -1451,7 +1452,7 @@ logfile_writename(void)
 
 	if (last_file_name && (Log_destination & LOG_DESTINATION_STDERR))
 	{
-		if (fprintf(fh, "stderr %s\n", last_file_name) < 0)
+		if (fprintf(fh, GUCV_STDERR " %s\n", last_file_name) < 0)
 		{
 			ereport(LOG,
 					(errcode_for_file_access(),
@@ -1464,7 +1465,7 @@ logfile_writename(void)
 
 	if (last_csv_file_name && (Log_destination & LOG_DESTINATION_CSVLOG))
 	{
-		if (fprintf(fh, "csvlog %s\n", last_csv_file_name) < 0)
+		if (fprintf(fh, GUCV_CSVLOG " %s\n", last_csv_file_name) < 0)
 		{
 			ereport(LOG,
 					(errcode_for_file_access(),
diff --git a/src/backend/utils/adt/misc.c b/src/backend/utils/adt/misc.c
index 53185e5..49c6da3 100644
--- a/src/backend/utils/adt/misc.c
+++ b/src/backend/utils/adt/misc.c
@@ -43,6 +43,7 @@
 #include "tcop/tcopprot.h"
 #include "utils/acl.h"
 #include "utils/builtins.h"
+#include "utils/guc_values.h"
 #include "utils/timestamp.h"
 
 #define atooid(x)  ((Oid) strtoul((x), NULL, 10))
@@ -913,10 +914,11 @@ pg_current_logfile(PG_FUNCTION_ARGS)
 		fmt = PG_ARGISNULL(0) ? NULL : PG_GETARG_TEXT_PP(0);
 		if (fmt != NULL) {
 			logfmt = text_to_cstring(fmt);
-			if ( (strcmp(logfmt, "stderr") != 0) &&
-				(strcmp(logfmt, "csvlog") != 0) ) {
+			if ( (strcmp(logfmt, GUCV_STDERR) != 0) &&
+				(strcmp(logfmt, GUCV_CSVLOG) != 0) ) {
 				ereport(ERROR,
-		(errmsg("log format %s not supported, possible values are stderr or csvlog", logfmt)));
+		(errmsg("log format %s not supported, possible values are "
+				GUCV_STDERR " or " GUCV_CSVLOG, logfmt)));
 				PG_RETURN_NULL();
 			}
 		}
@@ -1001,12 +1003,12 @@ pg_current_logfile(PG_FUNCTION_ARGS)
 		PG_RETURN_NULL();
 
 	/* Return null when csvlog is requested but we have a stderr log */
-	if ( (logfmt != NULL) && (strcmp(logfmt, "csvlog") == 0)
+	if ( (logfmt != NULL) && (strcmp(logfmt, GUCV_CSVLOG) == 0)
 			&& !(Log_destination & LOG_DESTINATION_CSVLOG) )
 		PG_RETURN_NULL();
 
 	/* Return null when stderr is requested but we have a csv log */
-	if ( (logfmt != NULL) && (strcmp(logfmt, "stderr") == 0)
+	if ( (logfmt != NULL) && (strcmp(logfmt, GUCV_STDERR) == 0)
 			&& !(Log_destination & LOG_DESTINATION_STDERR) )
 		PG_RETURN_NULL();