diff --git a/src/Data/Aeson/Yaml.hs b/src/Data/Aeson/Yaml.hs
index c9070c3..d1388a4 100644
--- a/src/Data/Aeson/Yaml.hs
+++ b/src/Data/Aeson/Yaml.hs
@@ -124,6 +124,8 @@ encodeText canMultiline alwaysQuote level s
   | canMultiline && "\n" `Text.isSuffixOf` s = encodeLines level (Text.lines s)
   -- s is a number, date, or boolString; single-quote
   | Text.all isNumberOrDateRelated s || isBoolString = singleQuote
+  -- s is a cird; single-quote
+  | isDigit headS && Text.all isCIDR tailS = singleQuote
   -- s should be quoted, AND s is not unsafe; single-quote
   | alwaysQuote && unquotable = singleQuote
   -- s should be quoted, OR s might be unsafe; double-quote
@@ -134,6 +136,7 @@ encodeText canMultiline alwaysQuote level s
     noQuote = b (Text.Encoding.encodeUtf8 s)
     singleQuote = bs "'" <> noQuote <> bs "'"
     headS = Text.head s
+    tailS = Text.tail s
     unquotable -- s is unquotable if all are True
      =
       s /= "" && -- s is not empty
@@ -152,6 +155,7 @@ encodeText canMultiline alwaysQuote level s
       (c >= 'A' && c <= 'Z') ||
       (c >= '0' && c <= '9') || c == '/' || c == '_' || c == '.' || c == '='
     isNumberOrDateRelated c = isDigit c || c == '.' || c == 'e' || c == '-'
+    isCIDR c = isDigit c || c == '.' || c == '/'
     isAllowed c = isSafeAscii c || c == '-' || c == ':' || c == ' '
 
 encodeLines :: Int -> [Text] -> Builder
diff --git a/test/Test/Data/Aeson/Yaml.hs b/test/Test/Data/Aeson/Yaml.hs
index 55c5fc4..8ae9d02 100644
--- a/test/Test/Data/Aeson/Yaml.hs
+++ b/test/Test/Data/Aeson/Yaml.hs
@@ -30,7 +30,7 @@ data TestCase =
 
 testCases :: [TestCase]
 testCases =
-  [tcDataTypes, tcNestedListsAndObjects, tcQuoted, tcEmptyList, tcHelloWorld]
+  [tcDataTypes, tcNestedListsAndObjects, tcQuoted, tcNetworkQuote, tcEmptyList, tcHelloWorld]
 
 tcEmptyList :: TestCase
 tcEmptyList =
@@ -132,6 +132,7 @@ tcNestedListsAndObjects =
                {
                   "command": [
                      "/data/bin/foo",
+                     "/42",
                      "--port=7654"
                   ],
                   "image": "ubuntu:latest",
@@ -180,6 +181,7 @@ spec:
       containers:
         - command:
             - /data/bin/foo
+            - /42
             - "--port=7654"
           image: ubuntu:latest
           name: "{{ .Release.Name }}-container"
@@ -209,6 +211,24 @@ tcQuoted =
     , tcAlwaysQuote = True
     }
 
+tcNetworkQuote :: TestCase
+tcNetworkQuote =
+  TestCase
+    { tcName = "Network CIDR single quote"
+    , tcInput =
+        [s|
+{ "ip": "127.0.0.1"
+, "net": "127.0.0.1/8"
+}
+|]
+    , tcOutput =
+        [s|ip: '127.0.0.1'
+net: '127.0.0.1/8'
+|]
+    , tcAlwaysQuote = False
+    }
+
+
 tcHelloWorld :: TestCase
 tcHelloWorld =
   TestCase
@@ -225,7 +245,7 @@ tcHelloWorld =
         }
       }
     ]
-    
+
   }
 }
 |]