diff --git a/pkgs/by-name/bo/boringssl/package.nix b/pkgs/by-name/bo/boringssl/package.nix
index 92cb25cba6aa..40bd420a157d 100644
--- a/pkgs/by-name/bo/boringssl/package.nix
+++ b/pkgs/by-name/bo/boringssl/package.nix
@@ -47,6 +47,9 @@ buildGoModule (finalAttrs: {
       # Needed with GCC 12 but breaks on darwin (with clang)
       "-Wno-error=stringop-overflow"
     ]
+    ++ lib.optionals stdenv.cc.isClang [
+      "-Wno-error=character-conversion"
+    ]
   );
 
   buildPhase = ''