2 files changed, 2 insertions, 2 deletions
diff --git a/api.cpp b/api.cpp
index efb4bdb..acf0fba 100644
--- a/api.cpp
+++ b/api.cpp
@@ -27,7 +27,7 @@ void Api::display_power(bool mode) {
     oledPower(&m_oled, mode);
 }
 
-int Api::display_write_string(int iScrollX, int x, int y, char *szMsg, int iSize, int bInvert, int bRender) {
+int Api::display_write_string(int iScrollX, int x, int y, const char *szMsg, int iSize, int bInvert, int bRender) {
     oledWriteString(&m_oled, iScrollX, x, y, szMsg, iSize, bInvert, 0);
     m_writebb_needed = true;
 }
diff --git a/api.hpp b/api.hpp
index 1a6d33f..0327f4f 100644
--- a/api.hpp
+++ b/api.hpp
@@ -38,7 +38,7 @@ class Api {
         void init();
         // Control the display's power (on or off)
         void display_power(bool mode);
-        int display_write_string(int iScrollX, int x, int y, char *szMsg, int iSize, int bInvert, int bRender);
+        int display_write_string(int iScrollX, int x, int y, const char *szMsg, int iSize, int bInvert, int bRender);
         void display_fill(unsigned char ucData, int bRender);
         void display_draw_line(int x1, int y1, int x2, int y2, int bRender);
         void display_draw_rectange(int x1, int y1, int x2, int y2, uint8_t ucColor, uint8_t bFilled);