diff --git a/codan/org.eclipse.cdt.codan.core.cxx/src/org/eclipse/cdt/codan/core/cxx/model/AbstractIndexAstChecker.java b/codan/org.eclipse.cdt.codan.core.cxx/src/org/eclipse/cdt/codan/core/cxx/model/AbstractIndexAstChecker.java
index 44287f7ea50..92cbfed1b00 100644
--- a/codan/org.eclipse.cdt.codan.core.cxx/src/org/eclipse/cdt/codan/core/cxx/model/AbstractIndexAstChecker.java
+++ b/codan/org.eclipse.cdt.codan.core.cxx/src/org/eclipse/cdt/codan/core/cxx/model/AbstractIndexAstChecker.java
@@ -197,11 +197,11 @@ public abstract class AbstractIndexAstChecker extends AbstractCheckerWithProblem
 				return locFactory.createProblemLocation(getFile(), start, end, line);
 			}
 		}
-		if (line == astLocation.getEndingLineNumber()) {
-			return locFactory.createProblemLocation(getFile(), astLocation.getNodeOffset(),
-					astLocation.getNodeOffset() + astLocation.getNodeLength(), line);
-		}
-		return locFactory.createProblemLocation(getFile(), line);
+		// If the raw signature has more than one line, we highlight only the code
+		// related to the problem.
+		int start = astLocation.getNodeOffset();
+		int end = start + astLocation.getNodeLength();
+		return locFactory.createProblemLocation(getFile(), start, end, line);
 	}
 
 	protected static boolean enclosedInMacroExpansion(IASTNode node) {
diff --git a/codan/org.eclipse.cdt.codan.core.test/src/org/eclipse/cdt/codan/core/internal/checkers/AssignmentToItselfCheckerTest.java b/codan/org.eclipse.cdt.codan.core.test/src/org/eclipse/cdt/codan/core/internal/checkers/AssignmentToItselfCheckerTest.java
index e3c5968d7fc..18c39ada406 100644
--- a/codan/org.eclipse.cdt.codan.core.test/src/org/eclipse/cdt/codan/core/internal/checkers/AssignmentToItselfCheckerTest.java
+++ b/codan/org.eclipse.cdt.codan.core.test/src/org/eclipse/cdt/codan/core/internal/checkers/AssignmentToItselfCheckerTest.java
@@ -11,6 +11,7 @@
 package org.eclipse.cdt.codan.core.internal.checkers;
 
 import org.eclipse.cdt.codan.core.test.CheckerTestCase;
+import org.eclipse.core.resources.IMarker;
 
 /**
  * Test for {@see AssignmentToItselfChecker} class
@@ -63,4 +64,18 @@ public class AssignmentToItselfCheckerTest extends CheckerTestCase {
 		loadCodeAndRun(getAboveComment());
 		checkNoErrors();
 	}
+
+	// void foo() {
+	//    int x = 0; x
+	//       = x;
+	// }
+	public void testMarkerOffset_Bug486610() throws Exception {
+		String code = getAboveComment();
+		loadCodeAndRun(code);
+		IMarker marker = checkErrorLine(2);
+		int start = marker.getAttribute(IMarker.CHAR_START, -1);
+		int end = marker.getAttribute(IMarker.CHAR_END, -1);
+		// The offset should start at the beginning of the expression "x = x"
+		assertEquals("x\n       = x", code.substring(start, end));
+	}
 }