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 4e05e2cf07c..795f2f8a32d 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
@@ -10978,4 +10978,12 @@ public class AST2CPPTests extends AST2TestBase {
 		IASTSimpleDeclaration sd = (IASTSimpleDeclaration) tu.getDeclarations()[0];
 		isParameterSignatureEqual(sd.getDeclarators()[0], "(int&&)");
 	}
+	
+	//	constexpr int waldo = 42;
+	public void testConstexprVariableIsConst_451091() throws Exception {
+		BindingAssertionHelper helper = getAssertionHelper();
+		ICPPVariable waldo = helper.assertNonProblem("waldo");
+		assertInstance(waldo.getType(), IQualifierType.class);
+		assertTrue(((IQualifierType) waldo.getType()).isConst());
+	}
 }
diff --git a/core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/dom/parser/cpp/semantics/CPPVisitor.java b/core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/dom/parser/cpp/semantics/CPPVisitor.java
index 4c88bfcb1fd..35ac854f633 100644
--- a/core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/dom/parser/cpp/semantics/CPPVisitor.java
+++ b/core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/dom/parser/cpp/semantics/CPPVisitor.java
@@ -2243,7 +2243,10 @@ public class CPPVisitor extends ASTQueries {
 	}
 
 	private static IType qualifyType(IType type, IASTDeclSpecifier declSpec) {
-		return SemanticUtil.addQualifiers(type, declSpec.isConst(), declSpec.isVolatile(), declSpec.isRestrict());
+		boolean isConst = declSpec.isConst() 
+				       || (declSpec instanceof ICPPASTDeclSpecifier 
+						   && ((ICPPASTDeclSpecifier) declSpec).isConstexpr());
+		return SemanticUtil.addQualifiers(type, isConst, declSpec.isVolatile(), declSpec.isRestrict());
 	}
 
 	private static IType createType(IType baseType, IASTDeclarator declarator) {