diff --git a/src/Data/Aeson/Yaml.hs b/src/Data/Aeson/Yaml.hs
index 4280d67..c9070c3 100644
--- a/src/Data/Aeson/Yaml.hs
+++ b/src/Data/Aeson/Yaml.hs
@@ -122,38 +122,24 @@ encodeText canMultiline alwaysQuote level s
   -- s is a value, not a map key, and contains newlines; can be inserted
   -- literally with `|` syntax
   | canMultiline && "\n" `Text.isSuffixOf` s = encodeLines level (Text.lines s)
-
-  | shouldSingleQuote = singleQuote
-
+  -- s is a number, date, or boolString; single-quote
+  | Text.all isNumberOrDateRelated s || isBoolString = 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
   | alwaysQuote || not unquotable = bl $ Data.Aeson.encode s
-
   -- otherwise; no quotes
   | otherwise = noQuote
   where
     noQuote = b (Text.Encoding.encodeUtf8 s)
-
-    shouldSingleQuote =
-            (Text.all isNumberOrDateRelated s && Text.any isDigit s)
-        ||  isBoolString
-        ||  Text.isPrefixOf " " s
-        ||  Text.isSuffixOf " " s
-            -- Quote if the string looks like a key
-        ||  Text.isInfixOf ":" s
-            -- s should be quoted, AND s is not unsafe; single-quote
-        ||  (alwaysQuote && unquotable)
-
     singleQuote = bs "'" <> noQuote <> bs "'"
-
     headS = Text.head s
-
     unquotable -- s is unquotable if all are True
      =
       s /= "" && -- s is not empty
       Text.all isAllowed s && -- s consists of acceptable chars
       (Data.Char.isAlpha headS || -- head of s is a char in A-Z or a-z or indicates a filepath
        headS == '/')
-
     isBoolString
       | Text.length s > 5 = False
       | otherwise =
@@ -161,14 +147,11 @@ encodeText canMultiline alwaysQuote level s
           "true" -> True
           "false" -> True
           _ -> False
-
     isSafeAscii c =
       (c >= 'a' && c <= 'z') ||
       (c >= 'A' && c <= 'Z') ||
       (c >= '0' && c <= '9') || c == '/' || c == '_' || c == '.' || c == '='
-
     isNumberOrDateRelated c = isDigit c || c == '.' || c == 'e' || 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 0eb52a0..55c5fc4 100644
--- a/test/Test/Data/Aeson/Yaml.hs
+++ b/test/Test/Data/Aeson/Yaml.hs
@@ -59,29 +59,24 @@ tcDataTypes =
    "piString": "3.14",
    "expString": "1e3",
    "leadingSpace" : " leading space",
-   "trailingSpace" : "trailing space ",
-   "colon" : "colon:",
    "leadingSymbol" : "!leading symbol",
    "asteriskString": "*",
    "multiLine": "The first line is followed by the\nsecond line\n",
    "multiLineWithSpaces": "         This has extra\n     spaces at the beginning\n",
    "notMultiline": "This won't be\nmulti-lined",
    "list": ["foo", "bar", "baz"],
-   "listEmpty": [],
-   "e": null
+   "listEmpty": []
 }
 |]
     , tcOutput =
         [s|asteriskString: "*"
 boolString: 'true'
-colon: 'colon:'
 dateString: '2038-01-19'
-e: null
 emptyObject: {}
 expString: '1e3'
 isFalse: false
 isTrue: true
-leadingSpace: ' leading space'
+leadingSpace: " leading space"
 leadingSymbol: "!leading symbol"
 list:
   - foo
@@ -99,7 +94,6 @@ nullValue: null
 numberString: '12345'
 piString: '3.14'
 "quoted ! key": true
-trailingSpace: 'trailing space '
 |]
     , tcAlwaysQuote = False
     }
@@ -187,7 +181,7 @@ spec:
         - command:
             - /data/bin/foo
             - "--port=7654"
-          image: 'ubuntu:latest'
+          image: ubuntu:latest
           name: "{{ .Release.Name }}-container"
           ports:
             - containerPort: 7654