diff --git a/contrib/ports/unix/example_app/iteropts.sh b/contrib/ports/unix/example_app/iteropts.sh
index 05ec0314..3856141f 100755
--- a/contrib/ports/unix/example_app/iteropts.sh
+++ b/contrib/ports/unix/example_app/iteropts.sh
@@ -14,7 +14,7 @@ do
     BUILDLOG=$(basename "$f" ".h").log
     echo testing $f
     echo testing $f >> $LOGFILE
-    rm $EXAPPDIR/lwipopts_test.h
+    rm -f $EXAPPDIR/lwipopts_test.h
     # cat the file to update its timestamp
     cat $f > $EXAPPDIR/lwipopts_test.h
     make TESTFLAGS="-DLWIP_OPTTEST_FILE -Wno-documentation" -j 4 1> $BUILDLOG 2>&1