diff --git a/src/IMG_ImageIO.m b/src/IMG_ImageIO.m
index 2d6eef01..1096210f 100644
--- a/src/IMG_ImageIO.m
+++ b/src/IMG_ImageIO.m
@@ -329,6 +329,7 @@ static CFDictionaryRef CreateHintDictionary(CFStringRef uti_string_hint)
                     palette->colors[i].r = entry[0];
                     palette->colors[i].g = entry[1];
                     palette->colors[i].b = entry[2];
+                    palette->colors[i].a = SDL_ALPHA_OPAQUE;
                     entry += num_components;
                 }
             }