diff --git a/contrib/scripts/checkpatch-feature-branch.sh b/contrib/scripts/checkpatch-feature-branch.sh
index 72e5903dae..292a429109 100755
--- a/contrib/scripts/checkpatch-feature-branch.sh
+++ b/contrib/scripts/checkpatch-feature-branch.sh
@@ -13,19 +13,24 @@ if printf '%s' "$HEAD" | grep -q '\.\.'; then
     # Check the explicitly specified range from the argument.
     REFS=( $(git log --reverse --format='%H' "$HEAD") ) || die "not a valid range (HEAD is $HEAD)"
 else
-    BASE_REF="refs/remotes/origin/"
+    BASE_REF="refs/remotes/origin"
+    NM_UPSTREAM_REMOTE=
 
     if [ "$NM_CHECKPATCH_FETCH_UPSTREAM" == 1 ]; then
-        git remote add nm-upstream https://gitlab.freedesktop.org/NetworkManager/NetworkManager.git
-        git fetch nm-upstream || die "failure to fetch from https://gitlab.freedesktop.org/NetworkManager/NetworkManager.git"
-        BASE_REF="refs/remotes/nm-upstream/"
+        NM_UPSTREAM_REMOTE="nm-upstream-$(date '+%Y%m%d-%H%M%S')-$RANDOM"
+        git remote add "$NM_UPSTREAM_REMOTE" https://gitlab.freedesktop.org/NetworkManager/NetworkManager.git
+        BASE_REF="refs/remotes/$NM_UPSTREAM_REMOTE"
+        git fetch "$NM_UPSTREAM_REMOTE" \
+            "refs/heads/master:$BASE_REF/master" \
+            "refs/heads/nm-*:$BASE_REF/nm-*" \
+            || die "failure to fetch from https://gitlab.freedesktop.org/NetworkManager/NetworkManager.git"
     fi
 
     # the argument is only a single ref (or the default "HEAD").
     # Find all commits that branch off one of the stable branches or master
     # and lead to $HEAD. These are the commits of the feature branch.
 
-    RANGES=( $(git show-ref | sed 's#^\(.*\) '"$BASE_REF"'\(master\|nm-1-[0-9]\+\)$#\1..'"$HEAD"'#p' -n) )
+    RANGES=( $(git show-ref | sed 's#^\(.*\) '"$BASE_REF/"'\(master\|nm-1-[0-9]\+\)$#\1..'"$HEAD"'#p' -n) )
 
     [ "${#RANGES[@]}" != 0 ] || die "cannot detect git-ranges (HEAD is $(git rev-parse "$HEAD"))"
 
@@ -36,6 +41,10 @@ else
         # stable nm-1-* branches. Just check the patch itself.
         REFS=( "$HEAD" )
     fi
+
+    if [ -n "$NM_UPSTREAM_REMOTE" ]; then
+        git remote remove "$NM_UPSTREAM_REMOTE"
+    fi
 fi
 
 SUCCESS=0