diff --git a/src/linter/quickfix.go b/src/linter/quickfix.go
index f2452e14..1ffc3e49 100644
--- a/src/linter/quickfix.go
+++ b/src/linter/quickfix.go
@@ -47,11 +47,11 @@ func (g *QuickFixGenerator) NullForNotNullableProperty(prop *ir.PropertyStmt) qu
 	}
 }
 
-func (g *QuickFixGenerator) NullableStringType(param *ir.Name) quickfix.TextEdit {
+func (g *QuickFixGenerator) NullableType(param *ir.Name) quickfix.TextEdit {
 	return quickfix.TextEdit{
 		StartPos:    param.Position.StartPos,
 		EndPos:      param.Position.EndPos,
-		Replacement: "?string",
+		Replacement: "?" + param.Value,
 	}
 }
 
diff --git a/src/linter/report.go b/src/linter/report.go
index 3f64ac82..62996cee 100644
--- a/src/linter/report.go
+++ b/src/linter/report.go
@@ -26,7 +26,7 @@ func addBuiltinCheckers(reg *CheckersRegistry) {
 		},
 
 		{
-			Name:     "nullableString",
+			Name:     "nullableType",
 			Default:  true,
 			Quickfix: true,
 			Comment:  "Report not nullable string can be null.",
diff --git a/src/linter/root_checker.go b/src/linter/root_checker.go
index fc22f660..72afbb2c 100644
--- a/src/linter/root_checker.go
+++ b/src/linter/root_checker.go
@@ -605,21 +605,17 @@ func (r *rootChecker) checkFuncParam(p *ir.Parameter) {
 		return true
 	})
 	r.CheckTypeHintFunctionParam(p)
-	r.CheckParamStringNullability(p)
+	r.CheckParamNullability(p)
 }
 
-func (r *rootChecker) CheckParamStringNullability(p *ir.Parameter) {
+func (r *rootChecker) CheckParamNullability(p *ir.Parameter) {
 	if param, ok := p.VariableType.(*ir.Name); ok {
-		if param.Value != "string" {
-			return
-		}
-
 		if defValue, ok := p.DefaultValue.(*ir.ConstFetchExpr); ok {
 			if defValue.Constant.Value != "null" {
 				return
 			}
-			r.walker.Report(param, LevelWarning, "nullableString", "string with null default value should be explicitly nullable")
-			r.walker.addQuickFix("nullableString", r.quickfix.NullableStringType(param))
+			r.walker.Report(param, LevelWarning, "nullableType", "parameter with null default value should be explicitly nullable")
+			r.walker.addQuickFix("nullableType", r.quickfix.NullableType(param))
 		}
 	}
 }