diff --git a/src/compiler/checker.ts b/src/compiler/checker.ts
index 852bf39c16d..c37066858a0 100644
--- a/src/compiler/checker.ts
+++ b/src/compiler/checker.ts
@@ -14972,9 +14972,12 @@ namespace ts {
             }
 
             function getTypeAtSwitchClause(flow: FlowSwitchClause): FlowType {
+                const expr = flow.switchStatement.expression;
+                if (containsMatchingReferenceDiscriminant(reference, expr)) {
+                    return declaredType;
+                }
                 const flowType = getTypeAtFlowNode(flow.antecedent);
                 let type = getTypeFromFlowType(flowType);
-                const expr = flow.switchStatement.expression;
                 if (isMatchingReference(reference, expr)) {
                     type = narrowTypeBySwitchOnDiscriminant(type, flow.switchStatement, flow.clauseStart, flow.clauseEnd);
                 }