diff --git a/build.xml b/build.xml
index 8eddf3e7..4629bb71 100644
--- a/build.xml
+++ b/build.xml
@@ -169,6 +169,33 @@
             </fileset>
         </delete>
 
+        <!-- Merge META-INF/services from TCVN-3, icu4j-charset-slim -->
+        <!-- find the icu4j-charset-slim jar -->
+        <path id="icu4j-slim.found">
+            <first>
+                <fileset dir="lib/charsets/">
+                    <include name="icu4j-charset-*.jar"/>
+                </fileset>
+            </first>
+        </path>
+        <pathconvert property="icu4j-slim.path" refid="icu4j-slim.found"/>
+
+        <!-- find the TCVN-3 jar -->
+        <path id="tcvn-3.found">
+            <first>
+                <fileset dir="lib/charsets/">
+                    <include name="TCVN-3*.jar"/>
+                </fileset>
+            </first>
+        </path>
+        <pathconvert property="tcvn-3.path" refid="tcvn-3.found"/>
+
+        <!-- merge service entries for CharsetProvider -->
+        <concat destfile="${out.dir}/libs-temp/META-INF/services/java.nio.charset.spi.CharsetProvider" fixlastline="true">
+            <zipentry zipfile="${icu4j-slim.path}" name="META-INF/services/java.nio.charset.spi.CharsetProvider"/>
+            <zipentry zipfile="${tcvn-3.path}" name="META-INF/services/java.nio.charset.spi.CharsetProvider"/>
+        </concat>
+
         <!-- Merge META-INF/services from PDFBOX, jpeg2000 and TwelveMonkeys -->
         <!-- find the TwelveMonkeys jar -->
         <path id="imageio-jpeg.found">
diff --git a/src/qz/common/AboutInfo.java b/src/qz/common/AboutInfo.java
index f369c29e..87d06c41 100644
--- a/src/qz/common/AboutInfo.java
+++ b/src/qz/common/AboutInfo.java
@@ -25,6 +25,7 @@
 import java.io.InputStreamReader;
 import java.lang.management.ManagementFactory;
 import java.net.URL;
+import java.nio.charset.Charset;
 import java.nio.charset.StandardCharsets;
 import java.security.GeneralSecurityException;
 import java.security.cert.CertificateEncodingException;
@@ -46,6 +47,7 @@ public static JSONObject gatherAbout(String domain, CertificateManager certifica
             about.put("environment", environment());
             about.put("ssl", ssl(certificateManager));
             about.put("libraries", libraries());
+            about.put("charsets", charsets());
         }
         catch(JSONException | GeneralSecurityException e) {
             log.error("Failed to write JSON data", e);
@@ -153,6 +155,19 @@ private static JSONObject libraries() throws JSONException {
         return libraries;
     }
 
+    private static JSONObject charsets() throws JSONException {
+        JSONObject charsets = new JSONObject();
+
+        SortedMap<String,Charset> avail = Charset.availableCharsets();
+        ArrayList<String> names = new ArrayList<>();
+        for(Map.Entry<String,Charset> entry : avail.entrySet()) {
+            names.add(entry.getValue().name());
+        }
+
+        charsets.put("charsets", Arrays.toString(names.toArray()));
+        return charsets;
+    }
+
     public static String getPreferredHostname() {
         return preferredHostname;
     }