diff --git a/openrtx/include/interfaces/graphics.h b/openrtx/include/interfaces/graphics.h
index fd003a92..8ea62d94 100644
--- a/openrtx/include/interfaces/graphics.h
+++ b/openrtx/include/interfaces/graphics.h
@@ -269,7 +269,7 @@ void gfx_drawSmeter(point_t start, uint16_t width, uint16_t height, float rssi,
  * @param sats: pointer to the array of satellites data
  * @param active_sats: bitset representing which sats are part of the fix
  */
-void gfx_drawGPSgraph(point_t start, uint16_t width, uint16_t height, sat_t *sats, uint16_t active_sats);
+void gfx_drawGPSgraph(point_t start, uint16_t width, uint16_t height, sat_t *sats, uint32_t active_sats);
 
 /**
  * Function to draw a compass of arbitrary size.
diff --git a/openrtx/include/state.h b/openrtx/include/state.h
index 1945ce4d..0838906f 100644
--- a/openrtx/include/state.h
+++ b/openrtx/include/state.h
@@ -49,7 +49,7 @@ typedef struct
     uint8_t satellites_tracked; // Number of tracked satellites
     uint8_t satellites_in_view; // Satellites in view
     sat_t satellites[12]; // Details about satellites in view
-    uint16_t active_sats; // Bitmap representing which sats are part of the fix
+    uint32_t active_sats; // Bitmap representing which sats are part of the fix
     float latitude;       // Latitude coordinates
     float longitude;      // Longitude coordinates
     float altitude;       // Antenna altitude above mean sea level (geoid) in m
diff --git a/openrtx/src/gps.c b/openrtx/src/gps.c
index 18b1e344..393649d0 100644
--- a/openrtx/src/gps.c
+++ b/openrtx/src/gps.c
@@ -67,7 +67,7 @@ void gps_taskFunc(char *line, int len, gps_t *state)
                 {
                     if (frame.sats[i] != 0)
                     {
-                        state->active_sats |= 1 << frame.sats[i];
+                        state->active_sats |= 1 << (frame.sats[i] - 1);
                     }
                 }
             }
diff --git a/openrtx/src/graphics.c b/openrtx/src/graphics.c
index ad5c1c37..145b0fdb 100644
--- a/openrtx/src/graphics.c
+++ b/openrtx/src/graphics.c
@@ -642,7 +642,7 @@ void gfx_drawGPSgraph(point_t start,
                       uint16_t width,
                       uint16_t height,
                       sat_t *sats,
-                      uint16_t active_sats)
+                      uint32_t active_sats)
 {
     color_t white =  {255, 255, 255, 255};
     color_t yellow = {250, 180, 19 , 255};
@@ -656,7 +656,7 @@ void gfx_drawGPSgraph(point_t start,
         bar_height = (height - 8) * sats[i].snr / 100 + 1;
         point_t bar_pos = {start.x + 2 + i * (bar_width + 2),
                            start.y + (height - 8) - bar_height};
-        color_t bar_color = (active_sats & 1 << sats[i].id) ? yellow : white;
+        color_t bar_color = (active_sats & 1 << (sats[i].id - 1)) ? yellow : white;
         gfx_drawRect(bar_pos, bar_width, bar_height, bar_color, true);
         snprintf(id_buf, 5, "%2d ", sats[i].id);
         point_t id_pos = {bar_pos.x, start.y + height};