diff --git a/prometheus/config-map.yaml b/prometheus/config-map.yaml
index 34664d0..8ae770f 100644
--- a/prometheus/config-map.yaml
+++ b/prometheus/config-map.yaml
@@ -27,7 +27,7 @@ data:
     - name: diskspace_low_worker
       rules:
       - alert: DiskspaceLow
-        expr: round((((node_memory_MemTotal_bytes{node=~"worker.*"} - node_memory_MemAvailable_bytes{node=~"worker.*"}) / node_memory_MemTotal_bytes{node=~"worker.*"}) * 100), 0.1) < 10
+        expr: round(node_filesystem_avail_bytes{mountpoint="/", node=~"worker.*"} / 1073742000, 0.1) < 50
         for: 1m
         labels:
           severity: warning
@@ -37,7 +37,7 @@ data:
     - name: diskspace_low_master
       rules:
       - alert: DiskspaceLow
-        expr: round((((node_memory_MemTotal_bytes{node=~"master.*"} - node_memory_MemAvailable_bytes{node=~"master.*"}) / node_memory_MemTotal_bytes{node=~"master.*"}) * 100), 0.1) < 2
+        expr: round(node_filesystem_avail_bytes{mountpoint="/", node=~"master.*"} / 1073742000, 0.1) < 10
         for: 1m
         labels:
           severity: warning