diff --git a/up.sh b/up.sh
index bd377e9..97cdbb1 100755
--- a/up.sh
+++ b/up.sh
@@ -7,6 +7,7 @@ export NIX_PATH
 PACKAGE_NAME=$1
 OLD_VERSION=$2
 NEW_VERSION=$3
+OK_TO_PR_AT=$4
 
 BRANCH_NAME="auto-update/$1"
 
@@ -170,6 +171,14 @@ if [[ -v DRY_RUN ]]
 then
     true
 else
+    CURRENT=$(date +%s)
+    if (( CURRENT < OK_TO_PR_AT ))
+    then
+        SLEEP_SECONDS=$(( OK_TO_PR_AT - CURRENT ))
+        echo "Sleeping $SLEEP_SECONDS seconds."
+        sleep "$SLEEP_SECONDS"
+    fi
+
     hub pull-request -m "$PR_MESSAGE"
 fi
 
diff --git a/ups.sh b/ups.sh
index 9ce6ede..8caa320 100755
--- a/ups.sh
+++ b/ups.sh
@@ -31,15 +31,16 @@ echo "
 
 $(date -Iseconds) New run of ups.sh" >> $LOG_FILE
 
+OK_TO_PR_AT=0
 IFS=$'\n'
 for a in $ARGUMENTS
 do
     unset IFS
     echo "$(date -Iseconds) $a" >> $LOG_FILE
-    if eval "$SCRIPT_DIR/up.sh $a 3>>$LOG_FILE"
+    if eval "$SCRIPT_DIR/up.sh $a $OK_TO_PR_AT 3>>$LOG_FILE"
     then
         echo "$(date -Iseconds) SUCCESS" >> $LOG_FILE
-        sleep 900
+        OK_TO_PR_AT=$(date +%s -d "+15 minutes")
     else
         echo "$(date -Iseconds) FAIL" >> $LOG_FILE
     fi