diff --git a/core/org.eclipse.cdt.core.tests/parser/org/eclipse/cdt/core/parser/tests/scanner/LexerTests.java b/core/org.eclipse.cdt.core.tests/parser/org/eclipse/cdt/core/parser/tests/scanner/LexerTests.java
index 23bdc2bd11a..9db25695eb1 100644
--- a/core/org.eclipse.cdt.core.tests/parser/org/eclipse/cdt/core/parser/tests/scanner/LexerTests.java
+++ b/core/org.eclipse.cdt.core.tests/parser/org/eclipse/cdt/core/parser/tests/scanner/LexerTests.java
@@ -201,7 +201,29 @@ public class LexerTests extends BaseTestCase {
 		id("ab");
 		eof();
 	}
-	
+
+	public void testLessColonColon() throws Exception {
+		// 2.5-3
+		// <: is treated as digraph [
+		init("<::>"); 
+		token(IToken.tLBRACKET);
+		token(IToken.tRBRACKET);
+		eof();
+
+		// <: is treated as digraph [
+		init("<:::"); 
+		token(IToken.tLBRACKET);
+		token(IToken.tCOLONCOLON);
+		eof();
+
+		// <:: is treated as < and ::
+		init("<::A"); 
+		token(IToken.tLT);
+		token(IToken.tCOLONCOLON);
+		token(IToken.tIDENTIFIER);
+		eof();
+	}
+
 	public void testWindowsLineEnding() throws Exception {
 		init("\n\n");
 		nl(); nl(); eof();
diff --git a/core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/parser/scanner/Lexer.java b/core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/parser/scanner/Lexer.java
index 439e2a910fb..40e1341fee3 100644
--- a/core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/parser/scanner/Lexer.java
+++ b/core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/parser/scanner/Lexer.java
@@ -582,8 +582,19 @@ final public class Lexer implements ITokenSequence {
 					} 
 					break;
 				case ':':
-					nextCharPhase3();
-					return newDigraphToken(IToken.tLBRACKET, start);
+					// 2.5-3
+					markPhase3();
+					if (nextCharPhase3() != ':') {
+						return newDigraphToken(IToken.tLBRACKET, start);
+					}
+					switch (nextCharPhase3()) {
+					case ':': case '>':
+						restorePhase3();
+						nextCharPhase3();
+						return newDigraphToken(IToken.tLBRACKET, start);
+					}
+					restorePhase3();
+					break;
 				case '%':
 					nextCharPhase3();
 					return newDigraphToken(IToken.tLBRACE, start);