diff --git a/src/share/classes/com/sun/tools/javac/parser/DocCommentParser.java b/src/share/classes/com/sun/tools/javac/parser/DocCommentParser.java
index 535dbd2692e789c583b972e866b42b68973676c9..b96c7c32669df8e849766584fd686201ba1e2715 100644
--- a/src/share/classes/com/sun/tools/javac/parser/DocCommentParser.java
+++ b/src/share/classes/com/sun/tools/javac/parser/DocCommentParser.java
@@ -280,7 +280,7 @@ public class DocCommentParser {
         try {
             nextChar();
             if (isIdentifierStart(ch)) {
-                Name name = readIdentifier();
+                Name name = readTagName();
                 TagParser tp = tagParsers.get(name);
                 if (tp == null) {
                     List<DCTree> content = blockContent();
@@ -329,7 +329,7 @@ public class DocCommentParser {
         try {
             nextChar();
             if (isIdentifierStart(ch)) {
-                Name name = readIdentifier();
+                Name name = readTagName();
                 skipWhitespace();
 
                 TagParser tp = tagParsers.get(name);
@@ -905,6 +905,14 @@ public class DocCommentParser {
         return names.fromChars(buf, start, bp - start);
     }
 
+    protected Name readTagName() {
+        int start = bp;
+        nextChar();
+        while (bp < buflen && (Character.isUnicodeIdentifierPart(ch) || ch == '.'))
+            nextChar();
+        return names.fromChars(buf, start, bp - start);
+    }
+
     protected boolean isJavaIdentifierStart(char ch) {
         return Character.isJavaIdentifierStart(ch);
     }
diff --git a/test/tools/doclint/CustomTagTest.java b/test/tools/doclint/CustomTagTest.java
index 3340dfb878c097f046fef97211fe910e5f2bc235..64ae347e4368c69630bd82478933f55f129c2397 100644
--- a/test/tools/doclint/CustomTagTest.java
+++ b/test/tools/doclint/CustomTagTest.java
@@ -1,17 +1,18 @@
 /*
  * @test /nodynamiccopyright/
- * @bug 8006248
+ * @bug 8006248 8028318
  * @summary DocLint should report unknown tags
  * @build DocLintTester
  * @run main DocLintTester CustomTagTest.java
  * @run main DocLintTester -XcustomTags: -ref CustomTagTest.out CustomTagTest.java
- * @run main DocLintTester -XcustomTags:customTag -ref CustomTagTestWithOption.out CustomTagTest.java
- * @run main DocLintTester -XcustomTags:customTag,anotherCustomTag -ref CustomTagTestWithOption.out CustomTagTest.java
+ * @run main DocLintTester -XcustomTags:customTag,custom.tag -ref CustomTagTestWithOption.out CustomTagTest.java
+ * @run main DocLintTester -XcustomTags:customTag,custom.tag,anotherCustomTag -ref CustomTagTestWithOption.out CustomTagTest.java
  * @author bpatel
  */
 
 /**
  * @customTag Text for a custom tag.
+ * @custom.tag Text for another custom tag.
  * @unknownTag Text for an unknown tag.
  */
 public class CustomTagTest {
diff --git a/test/tools/doclint/CustomTagTest.out b/test/tools/doclint/CustomTagTest.out
index 063e313071ece81c3b514067c58d8acabc46487d..4c58a3d3604fe7094d7761968cede88d2005562e 100644
--- a/test/tools/doclint/CustomTagTest.out
+++ b/test/tools/doclint/CustomTagTest.out
@@ -1,8 +1,11 @@
 CustomTagTest.java:14: error: unknown tag: customTag
  * @customTag Text for a custom tag.
    ^
-CustomTagTest.java:15: error: unknown tag: unknownTag
+CustomTagTest.java:15: error: unknown tag: custom.tag
+ * @custom.tag Text for another custom tag.
+   ^
+CustomTagTest.java:16: error: unknown tag: unknownTag
  * @unknownTag Text for an unknown tag.
    ^
-2 errors
+3 errors
 
diff --git a/test/tools/doclint/CustomTagTestWithOption.out b/test/tools/doclint/CustomTagTestWithOption.out
index 09150146e0cd17870df394beb9dd55a8ac8febb4..f5b67cf1d93ec35a7781a85c707e65e8af313224 100644
--- a/test/tools/doclint/CustomTagTestWithOption.out
+++ b/test/tools/doclint/CustomTagTestWithOption.out
@@ -1,4 +1,4 @@
-CustomTagTest.java:15: error: unknown tag: unknownTag
+CustomTagTest.java:16: error: unknown tag: unknownTag
  * @unknownTag Text for an unknown tag.
    ^
 1 error