diff --git a/pkgs/development/libraries/libressl/default.nix b/pkgs/development/libraries/libressl/default.nix
index 613f7d3a2b34..740d84072d1e 100644
--- a/pkgs/development/libraries/libressl/default.nix
+++ b/pkgs/development/libraries/libressl/default.nix
@@ -87,6 +87,15 @@ let
       platforms   = platforms.all;
       maintainers = with maintainers; [ thoughtpolice fpletz ];
       inherit knownVulnerabilities;
+
+      # OpenBSD believes that PowerPC should be always-big-endian;
+      # this assumption seems to have propagated into recent
+      # releases of libressl.  Since libressl is aliased to many
+      # other packages (e.g. netcat) it's important to fail early
+      # here, otherwise it's very difficult to figure out why
+      # libressl is getting dragged into a failing build.
+      badPlatforms = with lib.systems.inspect.patterns;
+        [ (lib.recursiveUpdate isPower64 isLittleEndian) ];
     };
   };