diff --git a/src/gps/RTC.cpp b/src/gps/RTC.cpp
index 25cd3ceff..a93a1ff62 100644
--- a/src/gps/RTC.cpp
+++ b/src/gps/RTC.cpp
@@ -397,7 +397,7 @@ uint32_t getValidTime(RTCQuality minQuality, bool local)
     return (currentQuality >= minQuality) ? getTime(local) : 0;
 }
 
-time_t gm_mktime(struct tm *tm)
+time_t gm_mktime(const struct tm *tm)
 {
 #if !MESHTASTIC_EXCLUDE_TZ
     time_t result = 0;
@@ -413,8 +413,8 @@ time_t gm_mktime(struct tm *tm)
     days_before_this_year -= 719162; // (1969 * 365 + 1969 / 4 - 1969 / 100 + 1969 / 400);
 
     // Now, within this tm->year, compute the days *before* this tm->month starts.
-    int days_before_month[12] = {0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334}; // non-leap year
-    int days_this_year_before_this_month = days_before_month[tm->tm_mon];                // tm->tm_mon is 0..11
+    static const int days_before_month[12] = {0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334}; // non-leap year
+    int days_this_year_before_this_month = days_before_month[tm->tm_mon];                             // tm->tm_mon is 0..11
 
     // If this is a leap year, and we're past February, add a day:
     if (tm->tm_mon >= 2 && (year % 4) == 0 && ((year % 100) != 0 || (year % 400) == 0)) {
diff --git a/src/gps/RTC.h b/src/gps/RTC.h
index 06dd34c16..cf6db0239 100644
--- a/src/gps/RTC.h
+++ b/src/gps/RTC.h
@@ -54,7 +54,7 @@ uint32_t getValidTime(RTCQuality minQuality, bool local = false);
 
 RTCSetResult readFromRTC();
 
-time_t gm_mktime(struct tm *tm);
+time_t gm_mktime(const struct tm *tm);
 
 #define SEC_PER_DAY 86400
 #define SEC_PER_HOUR 3600
diff --git a/src/graphics/draw/MenuHandler.h b/src/graphics/draw/MenuHandler.h
index 45fd0bf5f..1b964678b 100644
--- a/src/graphics/draw/MenuHandler.h
+++ b/src/graphics/draw/MenuHandler.h
@@ -140,7 +140,7 @@ struct ScreenColor {
     uint8_t b;
     bool useVariant;
 
-    ScreenColor(uint8_t rIn = 0, uint8_t gIn = 0, uint8_t bIn = 0, bool variantIn = false)
+    explicit ScreenColor(uint8_t rIn = 0, uint8_t gIn = 0, uint8_t bIn = 0, bool variantIn = false)
         : r(rIn), g(gIn), b(bIn), useVariant(variantIn)
     {
     }