diff --git a/device_mapper/libdm-report.c b/device_mapper/libdm-report.c
index 122ca83ab..24d350db5 100644
--- a/device_mapper/libdm-report.c
+++ b/device_mapper/libdm-report.c
@@ -2867,7 +2867,7 @@ static const char *_out_of_range_msg = "Field selection value %s out of supporte
 #define DELIM_DATE '-'
 #define DELIM_TIME ':'
 
-static int _days_in_month[12] = {31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
+static const int _days_in_month[12] = {31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
 
 static int _is_leap_year(long year)
 {
diff --git a/lib/report/report.c b/lib/report/report.c
index 319f423d2..da41d1635 100644
--- a/lib/report/report.c
+++ b/lib/report/report.c
@@ -851,7 +851,7 @@ static void _adjust_time_for_granularity(struct time_info *info, struct tm *tm,
 #define SECS_PER_HOUR   3600
 #define SECS_PER_DAY    ((time_t)86400)
 
-static int _days_in_month[12] = {31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
+static const int _days_in_month[12] = {31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
 
 static int _is_leap_year(long year)
 {
diff --git a/libdm/libdm-report.c b/libdm/libdm-report.c
index 87defe94a..d37bfceb0 100644
--- a/libdm/libdm-report.c
+++ b/libdm/libdm-report.c
@@ -2865,7 +2865,7 @@ static const char *_out_of_range_msg = "Field selection value %s out of supporte
 #define DELIM_DATE '-'
 #define DELIM_TIME ':'
 
-static int _days_in_month[12] = {31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
+static const int _days_in_month[12] = {31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
 
 static int _is_leap_year(long year)
 {