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 11dc769b395..0ab6bd5d649 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
@@ -11928,6 +11928,90 @@ public class AST2CPPTests extends AST2CPPTestBase {
 		checkUserDefinedLiteralIsRet(getAboveComment());
 	}
 
+	// class Ret {};
+	// Ret operator "" _X(char const * const s, unsigned long sz) { return Ret(); }
+	// auto test = "123"_X;
+	public void testUserDefinedLiteralConcatenation_528196_1a() throws Exception {
+		checkUserDefinedLiteralIsRet(getAboveComment());
+	}
+
+	// class Ret {};
+	// Ret operator "" _X(char const * volatile s, unsigned long sz) { return Ret(); }
+	// auto test = "123"_X;
+	public void testUserDefinedLiteralConcatenation_528196_1b() throws Exception {
+		checkUserDefinedLiteralIsRet(getAboveComment());
+	}
+
+	// class Ret {};
+	// Ret operator "" _X(char const * const volatile s, unsigned long sz) { return Ret(); }
+	// auto test = "123"_X;
+	public void testUserDefinedLiteralConcatenation_528196_1c() throws Exception {
+		checkUserDefinedLiteralIsRet(getAboveComment());
+	}
+
+	// class Ret {};
+	// Ret operator "" _X(char const * s, unsigned long const sz) { return Ret(); }
+	// auto test = "123"_X;
+	public void testUserDefinedLiteralConcatenation_528196_2a() throws Exception {
+		checkUserDefinedLiteralIsRet(getAboveComment());
+	}
+
+	// class Ret {};
+	// Ret operator "" _X(char const * s, unsigned long volatile sz) { return Ret(); }
+	// auto test = "123"_X;
+	public void testUserDefinedLiteralConcatenation_528196_2b() throws Exception {
+		checkUserDefinedLiteralIsRet(getAboveComment());
+	}
+
+	// class Ret {};
+	// Ret operator "" _X(char const * s, unsigned long const volatile sz) { return Ret(); }
+	// auto test = "123"_X;
+	public void testUserDefinedLiteralConcatenation_528196_2c() throws Exception {
+		checkUserDefinedLiteralIsRet(getAboveComment());
+	}
+
+	// class Ret {};
+	// Ret operator "" _X(unsigned long long const) { return Ret(); }
+	// auto test = 10_X;
+	public void testUserDefinedLiteralConcatenation_528196_3a() throws Exception {
+		checkUserDefinedLiteralIsRet(getAboveComment());
+	}
+
+	// class Ret {};
+	// Ret operator "" _X(unsigned long long volatile) { return Ret(); }
+	// auto test = 10_X;
+	public void testUserDefinedLiteralConcatenation_528196_3b() throws Exception {
+		checkUserDefinedLiteralIsRet(getAboveComment());
+	}
+
+	// class Ret {};
+	// Ret operator "" _X(unsigned long long const volatile) { return Ret(); }
+	// auto test = 10_X;
+	public void testUserDefinedLiteralConcatenation_528196_3c() throws Exception {
+		checkUserDefinedLiteralIsRet(getAboveComment());
+	}
+
+	// class Ret {};
+	// Ret operator "" _X(char const) { return Ret(); }
+	// auto test = 'a'_X;
+	public void testUserDefinedLiteralConcatenation_528196_4a() throws Exception {
+		checkUserDefinedLiteralIsRet(getAboveComment());
+	}
+
+	// class Ret {};
+	// Ret operator "" _X(char volatile) { return Ret(); }
+	// auto test = 'a'_X;
+	public void testUserDefinedLiteralConcatenation_528196_4b() throws Exception {
+		checkUserDefinedLiteralIsRet(getAboveComment());
+	}
+
+	// class Ret {};
+	// Ret operator "" _X(char const volatile) { return Ret(); }
+	// auto test = 'a'_X;
+	public void testUserDefinedLiteralConcatenation_528196_4c() throws Exception {
+		checkUserDefinedLiteralIsRet(getAboveComment());
+	}
+
 	// class Ret {};
 	// Ret operator "" _X(const char* s, unsigned sz) { return Ret(); }
 	// Ret operator "" _Y(const char* s, unsigned sz) { return Ret(); }
diff --git a/core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/dom/parser/cpp/semantics/CPPSemantics.java b/core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/dom/parser/cpp/semantics/CPPSemantics.java
index fbb36114cc1..84f7b656cb4 100644
--- a/core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/dom/parser/cpp/semantics/CPPSemantics.java
+++ b/core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/dom/parser/cpp/semantics/CPPSemantics.java
@@ -3302,7 +3302,7 @@ public class CPPSemantics {
 				} else if (kind == IASTLiteralExpression.lk_float_constant) {
 					type = new CPPBasicType(Kind.eDouble, IBasicType.IS_LONG);
 				}
-				return func.getParameters()[0].getType().isSameType(type);
+				return SemanticUtil.getNestedType(func.getParameters()[0].getType(), CVTYPE).isSameType(type);
 			}
 		}
 		return false;