diff --git a/lib/shared/search-index.js b/lib/shared/search-index.js
index 026eca102..626e94146 100644
--- a/lib/shared/search-index.js
+++ b/lib/shared/search-index.js
@@ -1,89 +1,76 @@
 // @flow
 
 import Tokenizer from 'tokenize-text';
 
+import RadixTree from './radix-tree.js';
+
 type Token = {
   index: number,
   match: {
     [i: number]: string,
     index: number,
     input: string,
     ...
   },
   offset: number,
   value: string,
   ...
 };
 
 type TokenizeFunc = (str: string) => Token[];
 const defaultTokenize: TokenizeFunc = new Tokenizer().words();
 
 class SearchIndex {
   tokenize: (str: string) => Token[];
-  fullTextIndex: { [token: string]: Set<string> };
-  partialTextIndex: { [token: string]: Set<string> };
+  radixTree: RadixTree<string> = new RadixTree<string>();
 
   constructor(inputTokenize?: TokenizeFunc) {
     this.tokenize = inputTokenize ?? defaultTokenize;
-    this.fullTextIndex = {};
-    this.partialTextIndex = {};
   }
 
   addAllPrefixes(id: string, value: string): void {
-    if (this.fullTextIndex[value] === undefined) {
-      this.fullTextIndex[value] = new Set();
-    }
-    this.fullTextIndex[value].add(id);
-    let partialString = '';
-    for (let i = 0; i < value.length; i++) {
-      const char = value[i];
-      partialString += char;
-      // TODO probably should do some stopwords here
-      if (this.partialTextIndex[partialString] === undefined) {
-        this.partialTextIndex[partialString] = new Set();
-      }
-      this.partialTextIndex[partialString].add(id);
-    }
+    this.radixTree.add(value, id);
   }
 
   addEntry(id: string, rawText: string) {
     const keywords = this.tokenize(rawText);
     for (const keyword of keywords) {
       const value = keyword.value.toLowerCase();
       this.addAllPrefixes(id, value);
     }
   }
 
   getSearchResults(query: string): string[] {
     const keywords = this.tokenize(query);
     if (keywords.length === 0) {
       return [];
     }
 
     const lastKeyword = keywords[keywords.length - 1];
     const lastKeywordValue = lastKeyword.value.toLowerCase();
     const lastMatchSet = lastKeyword.match.input.match(/\S$/)
-      ? this.partialTextIndex[lastKeywordValue]
-      : this.fullTextIndex[lastKeywordValue];
-    if (!lastMatchSet) {
+      ? this.radixTree.getAllMatchingPrefix(lastKeywordValue)
+      : this.radixTree.getAllMatchingExactly(lastKeywordValue);
+    if (lastMatchSet.length === 0) {
       return [];
     }
     const fullKeywords = keywords.slice(0, -1).map(k => k.value.toLowerCase());
 
-    let possibleMatches: string[] = Array.from(lastMatchSet);
+    let possibleMatches = lastMatchSet;
     for (const keyword of fullKeywords) {
-      const fullMatches = this.fullTextIndex[keyword];
-      if (!fullMatches) {
+      const fullMatches = this.radixTree.getAllMatchingExactly(keyword);
+      if (fullMatches.length === 0) {
         return [];
       }
-      possibleMatches = possibleMatches.filter(id => fullMatches.has(id));
+      const fullMatchesSet = new Set(fullMatches);
+      possibleMatches = possibleMatches.filter(id => fullMatchesSet.has(id));
       if (possibleMatches.length === 0) {
         return [];
       }
     }
 
     return possibleMatches;
   }
 }
 
 export default SearchIndex;
diff --git a/lib/shared/sentence-prefix-search-index.js b/lib/shared/sentence-prefix-search-index.js
index 928c025fa..bc85bd7cf 100644
--- a/lib/shared/sentence-prefix-search-index.js
+++ b/lib/shared/sentence-prefix-search-index.js
@@ -1,37 +1,33 @@
 // @flow
 
 import Tokenizer from 'tokenize-text';
 
 import SearchIndex from './search-index.js';
 
 // defaultTokenize used in SearchIndex splits on punctuation
 // We use this alternative because we only want to split on whitespace
 const tokenize = new Tokenizer().re(/\S+/);
 
 class SentencePrefixSearchIndex extends SearchIndex {
   entries: Set<string>;
 
   constructor() {
     super(tokenize);
     this.entries = new Set();
   }
 
   addEntry(id: string, rawText: string) {
     const keywords = this.tokenize(rawText);
     for (const keyword of keywords) {
       const value = rawText.slice(keyword.index).toLowerCase();
       this.addAllPrefixes(id, value);
     }
     this.entries.add(id);
   }
 
   getSearchResults(query: string): string[] {
-    const transformedQuery = query.toLowerCase();
-    if (this.partialTextIndex[transformedQuery]) {
-      return Array.from(this.partialTextIndex[transformedQuery]);
-    }
-    return [];
+    return this.radixTree.getAllMatchingPrefix(query.toLowerCase());
   }
 }
 
 export default SentencePrefixSearchIndex;