diff --git a/src/back/glsl/features.rs b/src/back/glsl/features.rs
index b1fff4d4bc..d6f3aae35d 100644
--- a/src/back/glsl/features.rs
+++ b/src/back/glsl/features.rs
@@ -98,7 +98,6 @@ impl FeaturesManager {
         check_feature!(ARRAY_OF_ARRAYS, 120, 310);
         check_feature!(IMAGE_LOAD_STORE, 130, 310);
         check_feature!(CONSERVATIVE_DEPTH, 130, 300);
-        check_feature!(CONSERVATIVE_DEPTH, 130, 300);
         check_feature!(NOPERSPECTIVE_QUALIFIER, 130);
         check_feature!(SAMPLE_QUALIFIER, 400, 320);
         check_feature!(CLIP_DISTANCE, 130, 300 /* with extension */);