diff --git a/debian/qualify-clang.sh b/debian/qualify-clang.sh
index 0b55a8d3..dd4faca8 100755
--- a/debian/qualify-clang.sh
+++ b/debian/qualify-clang.sh
@@ -294,7 +294,8 @@ fi
 clang-$VERSION -O3 -emit-llvm foo.c -c -o foo.bc
 chmod +x foo.bc
 # only run if the binfmt is installed correctly
-if /usr/sbin/update-binfmts --display llvm-$VERSION-runtime.binfmt &> /dev/null; then
+/usr/sbin/update-binfmts --display llvm-$VERSION-runtime.binfmt &> foo.log || true
+if grep -q "interpreter = /usr/bin/lli-" foo.log; then
     if ! ./foo.bc|grep -q "lli foo"; then
         echo "executing ./foo.bc failed"
         ./foo.bc