diff --git a/Documentation/filters-strings.md b/Documentation/filters-strings.md
index b4a7c50e..406ae8b3 100644
--- a/Documentation/filters-strings.md
+++ b/Documentation/filters-strings.md
@@ -184,6 +184,8 @@ https://developer.apple.com/library/content/documentation/Swift/Conceptual/Swift
 | `some$URL`             | `Some_URL`              |
 | `25 Ultra Light`       | `_25_Ultra_Light`       |
 | `26_extra_ultra_light` | `_26_extra_ultra_light` |
+| `apples.count`         | `Apples_Count`          |
+| `foo_bar.baz.qux-yay`  | `Foo_bar_Baz_Qux_Yay`   |
 
 **pretty**: Same as normal, but it will first replace whitespaces by underscores and apply the `snakeToCamelCase` filter.
 
@@ -191,9 +193,12 @@ https://developer.apple.com/library/content/documentation/Swift/Conceptual/Swift
 |------------------------|----------------------|
 | `hello`                | `Hello`              |
 | `42hello`              | `_42hello`           |
-| `some$URL`             | `Some_URL`           |
+| `some$URL`             | `SomeURL`            |
 | `25 Ultra Light`       | `_25UltraLight`      |
 | `26_extra_ultra_light` | `_26ExtraUltraLight` |
+| `apples.count`         | `ApplesCount`        |
+| `foo_bar.baz.qux-yay`  | `FooBarBazQuxYay`    |
+
 
 ## Filter: `titlecase`
 
diff --git a/Sources/Filters+Strings.swift b/Sources/Filters+Strings.swift
index 523b2c9f..ee3f4869 100644
--- a/Sources/Filters+Strings.swift
+++ b/Sources/Filters+Strings.swift
@@ -73,9 +73,9 @@ extension Filters {
       case .normal:
         return StencilSwiftKit.swiftIdentifier(from: string, replaceWithUnderscores: true)
       case .pretty:
-        string = string.replacingOccurrences(of: " ", with: "_")
+        string = StencilSwiftKit.swiftIdentifier(from: string, replaceWithUnderscores: true)
         string = try snakeToCamelCase(string, stripLeading: true)
-        return StencilSwiftKit.swiftIdentifier(from: string, replaceWithUnderscores: true)
+        return StencilSwiftKit.prefixWithUnderscoreIfNeeded(string: string)
       }
     }
 
diff --git a/Sources/SwiftIdentifier.swift b/Sources/SwiftIdentifier.swift
index 68d9e5e8..9a6ab369 100644
--- a/Sources/SwiftIdentifier.swift
+++ b/Sources/SwiftIdentifier.swift
@@ -32,7 +32,7 @@ private let tailRanges: [CountableClosedRange<Int>] = [
   0x30...0x39, 0x300...0x36F, 0x1dc0...0x1dff, 0x20d0...0x20ff, 0xfe20...0xfe2f
 ]
 
-private func identifierCharacterSets() -> (head: NSMutableCharacterSet, tail: NSMutableCharacterSet) {
+private func identifierCharacterSets(exceptions: String) -> (head: NSMutableCharacterSet, tail: NSMutableCharacterSet) {
   let addRange: (NSMutableCharacterSet, CountableClosedRange<Int>) -> Void = { (mcs, range) in
     mcs.addCharacters(in: NSRange(location: range.lowerBound, length: range.count))
   }
@@ -41,6 +41,7 @@ private func identifierCharacterSets() -> (head: NSMutableCharacterSet, tail: NS
   for range in headRanges {
     addRange(head, range)
   }
+  head.removeCharacters(in: exceptions)
 
   guard let tail = head.mutableCopy() as? NSMutableCharacterSet else {
     fatalError("Internal error: mutableCopy() should have returned a valid NSMutableCharacterSet")
@@ -48,6 +49,7 @@ private func identifierCharacterSets() -> (head: NSMutableCharacterSet, tail: NS
   for range in tailRanges {
     addRange(tail, range)
   }
+  tail.removeCharacters(in: exceptions)
 
   return (head, tail)
 }
@@ -56,14 +58,8 @@ func swiftIdentifier(from string: String,
                      forbiddenChars exceptions: String = "",
                      replaceWithUnderscores underscores: Bool = false) -> String {
 
-  let (head, tail) = identifierCharacterSets()
-  head.removeCharacters(in: exceptions)
-  tail.removeCharacters(in: exceptions)
+  let (_, tail) = identifierCharacterSets(exceptions: exceptions)
 
-  let chars = string.unicodeScalars
-  let firstChar = chars[chars.startIndex]
-
-  let prefix = !head.longCharacterIsMember(firstChar.value) && tail.longCharacterIsMember(firstChar.value) ? "_" : ""
   let parts = string.components(separatedBy: tail.inverted)
   let replacement = underscores ? "_" : ""
   let mappedParts = parts.map({ (string: String) -> String in
@@ -78,5 +74,19 @@ func swiftIdentifier(from string: String,
       return ""
     }
   })
-  return prefix + mappedParts.joined(separator: replacement)
+
+  let result = mappedParts.joined(separator: replacement)
+  return prefixWithUnderscoreIfNeeded(string: result, forbiddenChars: exceptions)
+}
+
+func prefixWithUnderscoreIfNeeded(string: String,
+                                  forbiddenChars exceptions: String = "") -> String {
+
+  let (head, tail) = identifierCharacterSets(exceptions: exceptions)
+
+  let chars = string.unicodeScalars
+  let firstChar = chars[chars.startIndex]
+  let prefix = !head.longCharacterIsMember(firstChar.value) && tail.longCharacterIsMember(firstChar.value) ? "_" : ""
+
+  return prefix + string
 }
diff --git a/Tests/StencilSwiftKitTests/SwiftIdentifierTests.swift b/Tests/StencilSwiftKitTests/SwiftIdentifierTests.swift
index fd035d02..b9ecef4e 100644
--- a/Tests/StencilSwiftKitTests/SwiftIdentifierTests.swift
+++ b/Tests/StencilSwiftKitTests/SwiftIdentifierTests.swift
@@ -70,6 +70,12 @@ extension SwiftIdentifierTests {
       "42hello": "_42hello",
       "some$URL": "Some_URL",
       "with space": "With_Space",
+      "apples.count": "Apples_Count",
+      ".SFNSDisplay": "_SFNSDisplay",
+      "Show-NavCtrl": "Show_NavCtrl",
+      "HEADER_TITLE": "HEADER_TITLE",
+      "multiLine\nKey": "MultiLine_Key",
+      "foo_bar.baz.qux-yay": "Foo_bar_Baz_Qux_Yay",
       "25 Ultra Light": "_25_Ultra_Light",
       "26_extra_ultra_light": "_26_extra_ultra_light",
       "12 @ 34 % 56 + 78 Hello world": "_12___34___56___78_Hello_World"
@@ -85,11 +91,17 @@ extension SwiftIdentifierTests {
     let expectations = [
       "hello": "Hello",
       "42hello": "_42hello",
-      "some$URL": "Some_URL",
+      "some$URL": "SomeURL",
       "with space": "WithSpace",
+      "apples.count": "ApplesCount",
+      ".SFNSDisplay": "SFNSDisplay",
+      "Show-NavCtrl": "ShowNavCtrl",
+      "HEADER_TITLE": "HeaderTitle",
+      "multiLine\nKey": "MultiLineKey",
+      "foo_bar.baz.qux-yay": "FooBarBazQuxYay",
       "25 Ultra Light": "_25UltraLight",
       "26_extra_ultra_light": "_26ExtraUltraLight",
-      "12 @ 34 % 56 + 78 Hello world": "_12_34_56_78HelloWorld"
+      "12 @ 34 % 56 + 78 Hello world": "_12345678HelloWorld"
     ]
 
     for (input, expected) in expectations {