diff --git a/icu4c/source/test/testdata/conversion.txt b/icu4c/source/test/testdata/conversion.txt
index c2fd59c6f4b..202dd7290cb 100644
--- a/icu4c/source/test/testdata/conversion.txt
+++ b/icu4c/source/test/testdata/conversion.txt
@@ -887,6 +887,13 @@ conversion:table(nofallback) {
           :intvector{ 0, 2, 4, 4, 6, 9, 10, 11 },
           :int{1}, :int{0}, "", "?", :bin{""}
         }
+        {
+          "ISO-2022-CN-EXT",
+          :bin{ 1b242b4d1b4f66791b242b4d1b4f216a },
+          "\u3667",
+          :intvector{ 14 },
+          :int{1}, :int{0}, "", "0", :bin{""}
+        }
       }
     }
 
diff --git a/icu4j/main/shared/data/testdata.jar b/icu4j/main/shared/data/testdata.jar
index ff5d486838d..ec096096144 100755
--- a/icu4j/main/shared/data/testdata.jar
+++ b/icu4j/main/shared/data/testdata.jar
@@ -1,3 +1,3 @@
 version https://git-lfs.github.com/spec/v1
-oid sha256:e0a6d624943d618593296da8962fe2e8a258a7bb431d452f99714189bf81a6f6
-size 773180
+oid sha256:a7ce8b58d416e6eae38a86180bcf591949db964a24e6016b5e393713bb42355a
+size 773227
diff --git a/icu4j/main/tests/charset/src/com/ibm/icu/dev/test/charset/TestCharset.java b/icu4j/main/tests/charset/src/com/ibm/icu/dev/test/charset/TestCharset.java
index a43fb7269ae..55bc3fc3e08 100644
--- a/icu4j/main/tests/charset/src/com/ibm/icu/dev/test/charset/TestCharset.java
+++ b/icu4j/main/tests/charset/src/com/ibm/icu/dev/test/charset/TestCharset.java
@@ -5532,4 +5532,39 @@ public class TestCharset extends TestFmwk {
             
         }
     }
+    
+    /*
+     * This is a port of ICU4C TestAmbiguousConverter in cintltst.
+     * Since there is no concept of ambiguous converters in ICU4J
+     * this test is merely for code coverage reasons.
+     */
+    public void TestAmbiguousConverter() {
+        byte [] inBytes = {
+                0x61, 0x5b, 0x5c
+        };
+        ByteBuffer src = ByteBuffer.wrap(inBytes);
+        CharBuffer trgt = CharBuffer.allocate(20);
+        
+        CoderResult result = CoderResult.UNDERFLOW;
+        CharsetProviderICU provider = new CharsetProviderICU();
+        String[] names = CharsetProviderICU.getAllNames();
+        
+        for (int i = 0; i < names.length; i++) {
+            Charset charset = provider.charsetForName(names[i]);
+            if (charset == null) {
+                /* We don't care about any failures because not all converters are available. */
+                continue;
+            }
+            CharsetDecoder decoder = charset.newDecoder();
+            
+            src.position(0);
+            trgt.clear();
+            
+            result = decoder.decode(src, trgt, true);
+            if (result.isError()) {
+                /* We don't care about any failures. */
+                continue;
+            }
+        }
+    }
 }