diff --git a/src/ply-gamma.c b/src/ply-gamma.c
index be47e9a..1f138d0 100644
--- a/src/ply-gamma.c
+++ b/src/ply-gamma.c
@@ -77,6 +77,7 @@
 
 bool ply_gamma_set(const char* file) {
   int r;
+  int crtc;
   drmModeCrtcPtr mode;
   GammaRamp* ramp;
 
@@ -100,7 +101,8 @@
     return false;
   }
 
-  mode = drmModeGetCrtc(fd, resources->crtcs[kInternalPanel]);
+  crtc = (kInternalPanel < resources->count_crtcs) ? kInternalPanel : 0;
+  mode = drmModeGetCrtc(fd, resources->crtcs[crtc]);
   r = drmModeCrtcSetGamma(fd,
                            mode->crtc_id,
                            mode->gamma_size,