diff --git a/core/org.eclipse.cdt.core.tests/parser/org/eclipse/cdt/internal/index/tests/IndexCBindingResolutionBugs.java b/core/org.eclipse.cdt.core.tests/parser/org/eclipse/cdt/internal/index/tests/IndexCBindingResolutionBugs.java
index d7168f6dc2e..d4395274638 100644
--- a/core/org.eclipse.cdt.core.tests/parser/org/eclipse/cdt/internal/index/tests/IndexCBindingResolutionBugs.java
+++ b/core/org.eclipse.cdt.core.tests/parser/org/eclipse/cdt/internal/index/tests/IndexCBindingResolutionBugs.java
@@ -110,7 +110,9 @@ public class IndexCBindingResolutionBugs extends IndexBindingResolutionTestBase
 		IParameter[] pars= f.getParameters();
 		assertEquals(1, pars.length);
 		IType type= pars[0].getType();
-		assertTrue(type instanceof ICompositeType);
+		assertInstance(type, ITypedef.class);
+		type= ((ITypedef) type).getType();
+		assertInstance(type, ICompositeType.class);
     }
 
     // typedef enum {
@@ -130,9 +132,10 @@ public class IndexCBindingResolutionBugs extends IndexBindingResolutionTestBase
 		IParameter[] pars= f.getParameters();
 		assertEquals(1, pars.length);
 		IType type= pars[0].getType();
+		assertInstance(type, ITypedef.class);
+		type= ((ITypedef) type).getType();
+		assertInstance(type, IEnumeration.class);
 		assertTrue(type instanceof IEnumeration);
-//		type= ((ITypedef) type).getType();
-//		assertTrue(type instanceof IEnumeration);
     }
     
     // int globalVar;
diff --git a/core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/pdom/dom/c/PDOMCParameter.java b/core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/pdom/dom/c/PDOMCParameter.java
index c47fdfde78b..ed320428f20 100644
--- a/core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/pdom/dom/c/PDOMCParameter.java
+++ b/core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/pdom/dom/c/PDOMCParameter.java
@@ -8,8 +8,8 @@
  * Contributors:
  *    QNX - Initial API and implementation
  *    Andrew Ferguson (Symbian)
+ *    Markus Schorn (Wind River Systems)
  *******************************************************************************/
-
 package org.eclipse.cdt.internal.core.pdom.dom.c;
 
 import org.eclipse.cdt.core.CCorePlugin;
@@ -18,7 +18,6 @@ import org.eclipse.cdt.core.dom.ast.IASTInitializer;
 import org.eclipse.cdt.core.dom.ast.IParameter;
 import org.eclipse.cdt.core.dom.ast.IProblemBinding;
 import org.eclipse.cdt.core.dom.ast.IType;
-import org.eclipse.cdt.core.dom.ast.ITypedef;
 import org.eclipse.cdt.core.index.IIndexFile;
 import org.eclipse.cdt.internal.core.Util;
 import org.eclipse.cdt.internal.core.index.IIndexCBindingConstants;
@@ -60,8 +59,6 @@ class PDOMCParameter extends PDOMNamedNode implements IParameter, IIndexFragment
 		try {
 			if(!(param instanceof IProblemBinding)) {
 				IType type = param.getType();
-				while(type instanceof ITypedef)
-					type = ((ITypedef)type).getType();
 				if (type != null) {
 					PDOMNode typeNode = getLinkageImpl().addType(this, type);
 					db.putInt(record + TYPE, typeNode != null ? typeNode.getRecord() : 0);
diff --git a/core/org.eclipse.cdt.ui.tests/ui/org/eclipse/cdt/ui/tests/text/contentassist2/CompletionTests.java b/core/org.eclipse.cdt.ui.tests/ui/org/eclipse/cdt/ui/tests/text/contentassist2/CompletionTests.java
index e17a818fc9e..acce9a2dd9b 100644
--- a/core/org.eclipse.cdt.ui.tests/ui/org/eclipse/cdt/ui/tests/text/contentassist2/CompletionTests.java
+++ b/core/org.eclipse.cdt.ui.tests/ui/org/eclipse/cdt/ui/tests/text/contentassist2/CompletionTests.java
@@ -157,6 +157,8 @@ public class CompletionTests extends AbstractContentAssistTest {
 	//		struct {int a3;} a4;
 	//		int b;
 	//	};
+	// typedef enum {__nix} _e204758;
+	// void _f204758(_e204758 x);
 
 
 	public CompletionTests(String name) {
@@ -1166,4 +1168,10 @@ public class CompletionTests extends AbstractContentAssistTest {
 		final String[] expected= {"a1", "a2", "u1", "u2", "a4", "b", "s206450"};
 		assertCompletionResults(expected);
 	}
+	
+	//  void test() {_f204758/*cursor*/
+	public void testTypedefToAnonymous_Bug204758() throws Exception {
+		final String[] expected= {"_f204758(_e204758 x) : void"};
+		assertCompletionResults(fCursorOffset, expected, COMPARE_DISP_STRINGS);
+	}
 }
diff --git a/core/org.eclipse.cdt.ui.tests/ui/org/eclipse/cdt/ui/tests/text/contentassist2/CompletionTests_PlainC.java b/core/org.eclipse.cdt.ui.tests/ui/org/eclipse/cdt/ui/tests/text/contentassist2/CompletionTests_PlainC.java
index 1212b88869d..324b31a2649 100644
--- a/core/org.eclipse.cdt.ui.tests/ui/org/eclipse/cdt/ui/tests/text/contentassist2/CompletionTests_PlainC.java
+++ b/core/org.eclipse.cdt.ui.tests/ui/org/eclipse/cdt/ui/tests/text/contentassist2/CompletionTests_PlainC.java
@@ -10,7 +10,6 @@
  *     Markus Schorn (Wind River Systems)
  *     IBM Corporation
  *******************************************************************************/
-
 package org.eclipse.cdt.ui.tests.text.contentassist2;
 
 import junit.framework.Test;
@@ -142,6 +141,10 @@ public class CompletionTests_PlainC extends AbstractContentAssistTest {
 	//		struct {int a3;} a4;
 	//		int b;
 	//	};
+	// #ifdef bug204758
+	// typedef enum {__nix} _e204758;
+	// void _f204758(_e204758 x);
+	// #endif
 	
 	//{DisturbWith.c}
 	// int gTemp;
@@ -951,4 +954,12 @@ public class CompletionTests_PlainC extends AbstractContentAssistTest {
 		final String[] expected= {"a1", "a2", "u1", "u2", "a4", "b"};
 		assertCompletionResults(expected);
 	}
+
+	// #define bug204758
+	///*include*/
+	//  void test() {_f204758/*cursor*/
+	public void testTypedefToAnonymous_Bug204758() throws Exception {
+		final String[] expected= {"_f204758(_e204758)"};
+		assertCompletionResults(expected);
+	}
 }