diff --git a/core/org.eclipse.cdt.core.tests/parser/org/eclipse/cdt/core/parser/tests/ast2/DOMLocationInclusionTests.java b/core/org.eclipse.cdt.core.tests/parser/org/eclipse/cdt/core/parser/tests/ast2/DOMLocationInclusionTests.java
index 0285de6f199..4a15757345d 100644
--- a/core/org.eclipse.cdt.core.tests/parser/org/eclipse/cdt/core/parser/tests/ast2/DOMLocationInclusionTests.java
+++ b/core/org.eclipse.cdt.core.tests/parser/org/eclipse/cdt/core/parser/tests/ast2/DOMLocationInclusionTests.java
@@ -226,6 +226,8 @@ public class DOMLocationInclusionTests extends AST2FileBasePluginTest {
             assertNotNull(incs);
             assertEquals(incs.length, 1);
             assertSoleFileLocation(incs[0], filename, code.indexOf("#inc"), "#include \"foo.h\"".length());
+            // test bug 166026
+            assertEquals(tu.getFilePath(), incs[0].getContainingFilename());
             
             checkInclude(incs[0], filename, code, "foo.h", false);
         }
diff --git a/core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/parser/scanner2/LocationMap.java b/core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/parser/scanner2/LocationMap.java
index a172403f452..571c5cc5134 100644
--- a/core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/parser/scanner2/LocationMap.java
+++ b/core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/parser/scanner2/LocationMap.java
@@ -2596,6 +2596,9 @@ public class LocationMap implements ILocationResolver, IScannerPreprocessorLog {
 	public String getContainingFilename(int offset) {
 		_Context c = findContextForOffset(offset);
 		if( c == null ) return EMPTY_STRING;
+		if (c instanceof _Inclusion && c.containsInDirective(offset, 1)) {
+			c = c.getParent();
+		}
 		_CompositeFileContext file = c.getContainingFileContext();
 		if( file == null ) return EMPTY_STRING;
 		return file.reader.getPath();