diff --git a/Codist/Helpers/CodeAnalysisHelper.Symbol.cs b/Codist/Helpers/CodeAnalysisHelper.Symbol.cs
index 7fc57ed2..78d63948 100644
--- a/Codist/Helpers/CodeAnalysisHelper.Symbol.cs
+++ b/Codist/Helpers/CodeAnalysisHelper.Symbol.cs
@@ -162,6 +162,14 @@ public static ISymbol GetAliasTarget(this ISymbol symbol) {
 			return symbol.Kind == SymbolKind.Alias ? (symbol as IAliasSymbol).Target : symbol;
 		}
 
+		public static IEnumerable<INamedTypeSymbol> GetContainingTypes(this ISymbol symbol) {
+			var t = symbol.ContainingType;
+			while (t != null) {
+				yield return t;
+				t = t.ContainingType;
+			}
+		}
+
 		public static ITypeSymbol ResolveElementType(this ITypeSymbol t) {
 			switch (t.Kind) {
 				case SymbolKind.ArrayType: return ResolveElementType(((IArrayTypeSymbol)t).ElementType);
diff --git a/Codist/Helpers/CodeAnalysisHelper.SymbolFinder.cs b/Codist/Helpers/CodeAnalysisHelper.SymbolFinder.cs
index a24082ea..9751d0a4 100644
--- a/Codist/Helpers/CodeAnalysisHelper.SymbolFinder.cs
+++ b/Codist/Helpers/CodeAnalysisHelper.SymbolFinder.cs
@@ -425,19 +425,19 @@ public static KeyValuePair<ISymbol, int>[] FindReferencingSymbols(this SyntaxNod
 			Predicate<SymbolUsageKind> usageFilter = null;
 			switch (symbol.Kind) {
 				case SymbolKind.NamedType:
-					if ((symbol as INamedTypeSymbol).IsBoundedGenericType()) {
+					// hack: In VS 2017 with Rosyln 2.10, we don't need this,
+					//       but in VS 2019, we have to do that, otherwise we will get nothing.
+					//       The same to SymbolKind.Method.
+					if ((symbol as INamedTypeSymbol).IsBoundedGenericType()
+						|| symbol.GetContainingTypes().Any(t => t.IsBoundedGenericType())) {
 						sign = symbol.ToDisplayString();
-						// hack: in VS 2017 with Rosyln 2.10, we don't need this,
-						//       but in VS 2019, we have to do that, otherwise we will get nothing
 						symbol = symbol.OriginalDefinition;
 					}
 					break;
 				case SymbolKind.Method:
 					var m = symbol as IMethodSymbol;
-					if (m.IsBoundedGenericMethod()) {
+					if (m.IsBoundedGenericMethod() || m.GetContainingTypes().Any(t => t.IsBoundedGenericType())) {
 						sign = symbol.ToDisplayString();
-						// hack: in VS 2017 with Rosyln 2.10, we don't need this,
-						//       but in VS 2019, we have to do that, otherwise we will get nothing
 						symbol = symbol.OriginalDefinition;
 					}
 					else if (m.IsExtensionMethod) {