diff --git a/lib/rexml/parsers/baseparser.rb b/lib/rexml/parsers/baseparser.rb
index f76aed07..84fc5ca5 100644
--- a/lib/rexml/parsers/baseparser.rb
+++ b/lib/rexml/parsers/baseparser.rb
@@ -83,9 +83,6 @@ class BaseParser
       ATTDEF_RE = /#{ATTDEF}/
       ATTLISTDECL_START = /\A\s*<!ATTLIST/um
       ATTLISTDECL_PATTERN = /\A\s*<!ATTLIST\s+#{NAME}(?:#{ATTDEF})*\s*>/um
-      NOTATIONDECL_START = /\A\s*<!NOTATION/um
-      PUBLIC = /\A\s*<!NOTATION\s+(\w[\-\w]*)\s+(PUBLIC)\s+(["'])(.*?)\3(?:\s+(["'])(.*?)\5)?\s*>/um
-      SYSTEM = /\A\s*<!NOTATION\s+(\w[\-\w]*)\s+(SYSTEM)\s+(["'])(.*?)\3\s*>/um
 
       TEXT_PATTERN = /\A([^<]*)/um
 
@@ -103,6 +100,10 @@ class BaseParser
       GEDECL = "<!ENTITY\\s+#{NAME}\\s+#{ENTITYDEF}\\s*>"
       ENTITYDECL = /\s*(?:#{GEDECL})|(?:#{PEDECL})/um
 
+      NOTATIONDECL_START = /\A\s*<!NOTATION/um
+      PUBLIC = /\A\s*<!NOTATION\s+#{NAME}\s+(PUBLIC)\s+#{PUBIDLITERAL}(?:\s+#{SYSTEMLITERAL})?\s*>/um
+      SYSTEM = /\A\s*<!NOTATION\s+#{NAME}\s+(SYSTEM)\s+#{SYSTEMLITERAL}\s*>/um
+
       EREFERENCE = /&(?!#{NAME};)/
 
       DEFAULT_ENTITIES = {
@@ -315,12 +316,22 @@ def pull_event
             md = nil
             if @source.match( PUBLIC )
               md = @source.match( PUBLIC, true )
-              vals = [md[1],md[2],md[4],md[6]]
+              pubid = system = nil
+              pubid_literal = md[3]
+              pubid = pubid_literal[1..-2] if pubid_literal # Remove quote
+              system_literal = md[4]
+              system = system_literal[1..-2] if system_literal # Remove quote
+              vals = [md[1], md[2], pubid, system]
             elsif @source.match( SYSTEM )
               md = @source.match( SYSTEM, true )
-              vals = [md[1],md[2],nil,md[4]]
+              system = nil
+              system_literal = md[3]
+              system = system_literal[1..-2] if system_literal # Remove quote
+              vals = [md[1], md[2], nil, system]
             else
-              raise REXML::ParseException.new( "error parsing notation: no matching pattern", @source )
+              details = notation_decl_invalid_details
+              message = "Malformed notation declaration: #{details}"
+              raise REXML::ParseException.new(message, @source)
             end
             return [ :notationdecl, *vals ]
           when DOCTYPE_END
@@ -569,6 +580,42 @@ def parse_attributes(prefixes, curr_ns)
         end
         return attributes, closed
       end
+
+      def notation_decl_invalid_details
+        name = /#{NOTATIONDECL_START}\s+#{NAME}/um
+        public = /#{name}\s+PUBLIC/um
+        system = /#{name}\s+SYSTEM/um
+        if @source.match(/#{NOTATIONDECL_START}\s*>/um)
+          return "name is missing"
+        elsif not @source.match(/#{name}[\s>]/um)
+          return "invalid name"
+        elsif @source.match(/#{name}\s*>/um)
+          return "ID type is missing"
+        elsif not @source.match(/#{name}\s+(?:PUBLIC|SYSTEM)[\s>]/um)
+          return "invalid ID type"
+        elsif @source.match(/#{public}/um)
+          if @source.match(/#{public}\s*>/um)
+            return "public ID literal is missing"
+          elsif not @source.match(/#{public}\s+#{PUBIDLITERAL}/um)
+            return "invalid public ID literal"
+          elsif @source.match(/#{public}\s+#{PUBIDLITERAL}[^\s>]/um)
+            return "garbage after public ID literal"
+          elsif not @source.match(/#{public}\s+#{PUBIDLITERAL}\s+#{SYSTEMLITERAL}/um)
+            return "invalid system literal"
+          elsif not @source.match(/#{public}\s+#{PUBIDLITERAL}\s+#{SYSTEMLITERAL}\s*>/um)
+            return "garbage after system literal"
+          end
+        elsif @source.match(/#{system}/um)
+          if @source.match(/#{system}\s*>/um)
+            return "system literal is missing"
+          elsif not @source.match(/#{system}\s+#{SYSTEMLITERAL}/um)
+            return "invalid system literal"
+          elsif not @source.match(/#{system}\s+#{SYSTEMLITERAL}\s*>/um)
+            return "garbage after system literal"
+          end
+        end
+        "end > is missing"
+      end
     end
   end
 end
diff --git a/test/parse/test_notation_declaration.rb b/test/parse/test_notation_declaration.rb
index 0d29f0d8..fbd29e2a 100644
--- a/test/parse/test_notation_declaration.rb
+++ b/test/parse/test_notation_declaration.rb
@@ -23,10 +23,100 @@ def test_name
         doctype = parse("<!NOTATION name PUBLIC 'urn:public-id'>")
         assert_equal("name", doctype.notation("name").name)
       end
+
+      def test_no_name
+        exception = assert_raise(REXML::ParseException) do
+          parse(<<-INTERNAL_SUBSET)
+<!NOTATION>
+          INTERNAL_SUBSET
+        end
+        assert_equal(<<-DETAIL.chomp, exception.to_s)
+Malformed notation declaration: name is missing
+Line: 5
+Position: 72
+Last 80 unconsumed characters:
+ <!NOTATION>  ]> <r/> 
+        DETAIL
+      end
+
+      def test_invalid_name
+        exception = assert_raise(REXML::ParseException) do
+          parse(<<-INTERNAL_SUBSET)
+<!NOTATION '>
+          INTERNAL_SUBSET
+        end
+        assert_equal(<<-DETAIL.chomp, exception.to_s)
+Malformed notation declaration: invalid name
+Line: 5
+Position: 74
+Last 80 unconsumed characters:
+ <!NOTATION '>  ]> <r/> 
+        DETAIL
+      end
+
+      def test_no_id_type
+        exception = assert_raise(REXML::ParseException) do
+          parse(<<-INTERNAL_SUBSET)
+<!NOTATION name>
+          INTERNAL_SUBSET
+        end
+        assert_equal(<<-DETAIL.chomp, exception.to_s)
+Malformed notation declaration: ID type is missing
+Line: 5
+Position: 77
+Last 80 unconsumed characters:
+ <!NOTATION name>  ]> <r/> 
+        DETAIL
+      end
+
+      def test_invalid_id_type
+        exception = assert_raise(REXML::ParseException) do
+          parse(<<-INTERNAL_SUBSET)
+<!NOTATION name INVALID>
+          INTERNAL_SUBSET
+        end
+        assert_equal(<<-DETAIL.chomp, exception.to_s)
+Malformed notation declaration: invalid ID type
+Line: 5
+Position: 85
+Last 80 unconsumed characters:
+ <!NOTATION name INVALID>  ]> <r/> 
+        DETAIL
+      end
     end
 
     class TestExternalID < self
       class TestSystem < self
+        def test_no_literal
+          exception = assert_raise(REXML::ParseException) do
+            parse(<<-INTERNAL_SUBSET)
+<!NOTATION name SYSTEM>
+            INTERNAL_SUBSET
+          end
+          assert_equal(<<-DETAIL.chomp, exception.to_s)
+Malformed notation declaration: system literal is missing
+Line: 5
+Position: 84
+Last 80 unconsumed characters:
+ <!NOTATION name SYSTEM>  ]> <r/> 
+          DETAIL
+        end
+
+        def test_garbage_after_literal
+          exception = assert_raise(REXML::ParseException) do
+            parse(<<-INTERNAL_SUBSET)
+<!NOTATION name SYSTEM 'system-literal'x'>
+            INTERNAL_SUBSET
+          end
+          assert_equal(<<-DETAIL.chomp, exception.to_s)
+Malformed notation declaration: garbage after system literal
+Line: 5
+Position: 103
+Last 80 unconsumed characters:
+ <!NOTATION name SYSTEM 'system-literal'x'>  ]> <r/> 
+          DETAIL
+        end
+
         def test_single_quote
           doctype = parse(<<-INTERNAL_SUBSET)
 <!NOTATION name SYSTEM 'system-literal'>
@@ -44,6 +134,21 @@ def test_double_quote
 
       class TestPublic < self
         class TestPublicIDLiteral < self
+          def test_content_double_quote
+            exception = assert_raise(REXML::ParseException) do
+              parse(<<-INTERNAL_SUBSET)
+<!NOTATION name PUBLIC 'double quote " is invalid' "system-literal">
+              INTERNAL_SUBSET
+            end
+            assert_equal(<<-DETAIL.chomp, exception.to_s)
+Malformed notation declaration: invalid public ID literal
+Line: 5
+Position: 129
+Last 80 unconsumed characters:
+ <!NOTATION name PUBLIC 'double quote " is invalid' "system-literal">  ]> <r/> 
+            DETAIL
+          end
+
           def test_single_quote
             doctype = parse(<<-INTERNAL_SUBSET)
 <!NOTATION name PUBLIC 'public-id-literal' "system-literal">
@@ -60,6 +165,21 @@ def test_double_quote
         end
 
         class TestSystemLiteral < self
+          def test_garbage_after_literal
+            exception = assert_raise(REXML::ParseException) do
+              parse(<<-INTERNAL_SUBSET)
+<!NOTATION name PUBLIC 'public-id-literal' 'system-literal'x'>
+              INTERNAL_SUBSET
+            end
+            assert_equal(<<-DETAIL.chomp, exception.to_s)
+Malformed notation declaration: garbage after system literal
+Line: 5
+Position: 123
+Last 80 unconsumed characters:
+ <!NOTATION name PUBLIC 'public-id-literal' 'system-literal'x'>  ]> <r/> 
+           DETAIL
+          end
+
           def test_single_quote
             doctype = parse(<<-INTERNAL_SUBSET)
 <!NOTATION name PUBLIC "public-id-literal" 'system-literal'>
@@ -96,5 +216,66 @@ def test_public_system
         end
       end
     end
+
+    class TestPublicID < self
+      def test_no_literal
+        exception = assert_raise(REXML::ParseException) do
+          parse(<<-INTERNAL_SUBSET)
+<!NOTATION name PUBLIC>
+          INTERNAL_SUBSET
+        end
+        assert_equal(<<-DETAIL.chomp, exception.to_s)
+Malformed notation declaration: public ID literal is missing
+Line: 5
+Position: 84
+Last 80 unconsumed characters:
+ <!NOTATION name PUBLIC>  ]> <r/> 
+        DETAIL
+      end
+
+      def test_literal_content_double_quote
+        exception = assert_raise(REXML::ParseException) do
+          parse(<<-INTERNAL_SUBSET)
+<!NOTATION name PUBLIC 'double quote " is invalid in PubidLiteral'>
+          INTERNAL_SUBSET
+        end
+        assert_equal(<<-DETAIL.chomp, exception.to_s)
+Malformed notation declaration: invalid public ID literal
+Line: 5
+Position: 128
+Last 80 unconsumed characters:
+ <!NOTATION name PUBLIC 'double quote \" is invalid in PubidLiteral'>  ]> <r/> 
+        DETAIL
+      end
+
+      def test_garbage_after_literal
+        exception = assert_raise(REXML::ParseException) do
+          parse(<<-INTERNAL_SUBSET)
+<!NOTATION name PUBLIC 'public-id-literal'x'>
+          INTERNAL_SUBSET
+        end
+        assert_equal(<<-DETAIL.chomp, exception.to_s)
+Malformed notation declaration: garbage after public ID literal
+Line: 5
+Position: 106
+Last 80 unconsumed characters:
+ <!NOTATION name PUBLIC 'public-id-literal'x'>  ]> <r/> 
+        DETAIL
+      end
+
+      def test_literal_single_quote
+        doctype = parse(<<-INTERNAL_SUBSET)
+<!NOTATION name PUBLIC 'public-id-literal'>
+        INTERNAL_SUBSET
+        assert_equal("public-id-literal", doctype.notation("name").public)
+      end
+
+      def test_literal_double_quote
+        doctype = parse(<<-INTERNAL_SUBSET)
+<!NOTATION name PUBLIC "public-id-literal">
+        INTERNAL_SUBSET
+        assert_equal("public-id-literal", doctype.notation("name").public)
+      end
+    end
   end
 end