diff --git a/VoiceInk/Services/WordReplacementService.swift b/VoiceInk/Services/WordReplacementService.swift
index 2c6fe85..1b84858 100644
--- a/VoiceInk/Services/WordReplacementService.swift
+++ b/VoiceInk/Services/WordReplacementService.swift
@@ -13,14 +13,14 @@ class WordReplacementService {
         
         var modifiedText = text
         
-        // Apply each replacement (case-insensitive, whole word)
+        // Apply replacements (case-insensitive)
         for (original, replacement) in replacements {
             let isPhrase = original.contains(" ") || original.trimmingCharacters(in: .whitespacesAndNewlines) != original
 
-            if isPhrase {
-                 modifiedText = modifiedText.replacingOccurrences(of: original, with: replacement, options: .caseInsensitive)
+            if isPhrase || !usesWordBoundaries(for: original) {
+                modifiedText = modifiedText.replacingOccurrences(of: original, with: replacement, options: .caseInsensitive)
             } else {
-                // Create a regular expression that matches the word boundaries
+                // Use word boundaries for spaced languages
                 let pattern = "\\b\(NSRegularExpression.escapedPattern(for: original))\\b"
                 if let regex = try? NSRegularExpression(pattern: pattern, options: .caseInsensitive) {
                     let range = NSRange(modifiedText.startIndex..., in: modifiedText)
@@ -36,4 +36,25 @@ class WordReplacementService {
         
         return modifiedText
     }
+
+    private func usesWordBoundaries(for text: String) -> Bool {
+        // Returns false for languages without spaces (CJK, Thai), true for spaced languages
+        let nonSpacedScripts: [ClosedRange<UInt32>] = [
+            0x3040...0x309F, // Hiragana
+            0x30A0...0x30FF, // Katakana
+            0x4E00...0x9FFF, // CJK Unified Ideographs
+            0xAC00...0xD7AF, // Hangul Syllables
+            0x0E00...0x0E7F, // Thai
+        ]
+
+        for scalar in text.unicodeScalars {
+            for range in nonSpacedScripts {
+                if range.contains(scalar.value) {
+                    return false
+                }
+            }
+        }
+
+        return true
+    }
 }