diff --git a/core/org.eclipse.cdt.core.tests/parser/org/eclipse/cdt/core/parser/tests/ast2/AST2CPPTests.java b/core/org.eclipse.cdt.core.tests/parser/org/eclipse/cdt/core/parser/tests/ast2/AST2CPPTests.java
index 4f7179838f4..9f1b8e148b7 100644
--- a/core/org.eclipse.cdt.core.tests/parser/org/eclipse/cdt/core/parser/tests/ast2/AST2CPPTests.java
+++ b/core/org.eclipse.cdt.core.tests/parser/org/eclipse/cdt/core/parser/tests/ast2/AST2CPPTests.java
@@ -6134,6 +6134,14 @@ public class AST2CPPTests extends AST2BaseTest {
             ba.assertProblem("a; // should not resolve", 1);
         }
     }
+    
+    //    namespace ns {
+    //    	template<typename T> class CT {};
+    //    }
+    //    using ns::CT<int>;
+    public void testTemplateIDInUsingDecl_251199() throws Exception {
+        parseAndCheckBindings(getAboveComment(), ParserLanguage.CPP);
+    }
 
 	//	void f();
 	//	
diff --git a/core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/dom/parser/cpp/semantics/CPPTemplates.java b/core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/dom/parser/cpp/semantics/CPPTemplates.java
index 06c6a574995..c5cdc6c4c73 100644
--- a/core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/dom/parser/cpp/semantics/CPPTemplates.java
+++ b/core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/dom/parser/cpp/semantics/CPPTemplates.java
@@ -470,10 +470,14 @@ public class CPPTemplates {
 			parent = parent.getParent();
 		}
 
-		IASTNode decl = parent.getParent();
-		while (!(decl instanceof IASTDeclaration))
-			decl = decl.getParent();
-		decl = decl.getParent();
+		IASTNode decl= parent;
+		while (decl != null) {
+			if (decl instanceof IASTDeclaration) {
+				decl= decl.getParent();
+				break;
+			}
+			decl= decl.getParent();
+		}
 
 		try {
 			if (decl instanceof ICPPASTExplicitTemplateInstantiation &&