diff --git a/src/compiler/checker.ts b/src/compiler/checker.ts
index dde8033d1e976..e4ea3740a62f6 100644
--- a/src/compiler/checker.ts
+++ b/src/compiler/checker.ts
@@ -7640,11 +7640,11 @@ namespace ts {
                 if (members.has(leftProp.name)) {
                     const rightProp = members.get(leftProp.name);
                     const rightType = getTypeOfSymbol(rightProp);
-                    if (maybeTypeOfKind(rightType, TypeFlags.Undefined) || rightProp.flags & SymbolFlags.Optional) {
+                    if (rightProp.flags & SymbolFlags.Optional) {
                         const declarations: Declaration[] = concatenate(leftProp.declarations, rightProp.declarations);
                         const flags = SymbolFlags.Property | (leftProp.flags & SymbolFlags.Optional);
                         const result = createSymbol(flags, leftProp.name);
-                        result.type = getUnionType([getTypeOfSymbol(leftProp), getTypeWithFacts(rightType, TypeFacts.NEUndefined)]);
+                        result.type = getUnionType([getTypeOfSymbol(leftProp), rightType]);
                         result.leftSpread = leftProp;
                         result.rightSpread = rightProp;
                         result.declarations = declarations;
diff --git a/tests/baselines/reference/objectSpreadStrictNull.errors.txt b/tests/baselines/reference/objectSpreadStrictNull.errors.txt
new file mode 100644
index 0000000000000..f3c5cc7de25b0
--- /dev/null
+++ b/tests/baselines/reference/objectSpreadStrictNull.errors.txt
@@ -0,0 +1,84 @@
+tests/cases/conformance/types/spread/objectSpreadStrictNull.ts(9,9): error TS2322: Type '{ sn: string | number | undefined; }' is not assignable to type '{ sn: string | number; }'.
+  Types of property 'sn' are incompatible.
+    Type 'string | number | undefined' is not assignable to type 'string | number'.
+      Type 'undefined' is not assignable to type 'string | number'.
+tests/cases/conformance/types/spread/objectSpreadStrictNull.ts(10,9): error TS2322: Type '{ sn: string | number | undefined; }' is not assignable to type '{ sn: string | number; }'.
+  Types of property 'sn' are incompatible.
+    Type 'string | number | undefined' is not assignable to type 'string | number'.
+      Type 'undefined' is not assignable to type 'string | number'.
+tests/cases/conformance/types/spread/objectSpreadStrictNull.ts(14,9): error TS2322: Type '{ sn: number | undefined; }' is not assignable to type '{ sn: string | number; }'.
+  Types of property 'sn' are incompatible.
+    Type 'number | undefined' is not assignable to type 'string | number'.
+      Type 'undefined' is not assignable to type 'string | number'.
+tests/cases/conformance/types/spread/objectSpreadStrictNull.ts(15,9): error TS2322: Type '{ sn: number | undefined; }' is not assignable to type '{ sn: string | number; }'.
+  Types of property 'sn' are incompatible.
+    Type 'number | undefined' is not assignable to type 'string | number'.
+      Type 'undefined' is not assignable to type 'string | number'.
+tests/cases/conformance/types/spread/objectSpreadStrictNull.ts(18,9): error TS2322: Type '{ sn: string | number | undefined; }' is not assignable to type '{ sn: string | number | boolean; }'.
+  Types of property 'sn' are incompatible.
+    Type 'string | number | undefined' is not assignable to type 'string | number | boolean'.
+      Type 'undefined' is not assignable to type 'string | number | boolean'.
+tests/cases/conformance/types/spread/objectSpreadStrictNull.ts(28,7): error TS2322: Type '{ title: undefined; yearReleased: number; }' is not assignable to type 'Movie'.
+  Types of property 'title' are incompatible.
+    Type 'undefined' is not assignable to type 'string'.
+
+
+==== tests/cases/conformance/types/spread/objectSpreadStrictNull.ts (6 errors) ====
+    function f(
+        definiteBoolean: { sn: boolean },
+        definiteString: { sn: string },
+        optionalString: { sn?: string },
+        optionalNumber: { sn?: number },
+        undefinedString: { sn: string | undefined },
+        undefinedNumber: { sn: number | undefined }) {
+        // optional
+        let optionalUnionStops: { sn: string | number } = { ...definiteBoolean, ...definiteString, ...optionalNumber };
+            ~~~~~~~~~~~~~~~~~~
+!!! error TS2322: Type '{ sn: string | number | undefined; }' is not assignable to type '{ sn: string | number; }'.
+!!! error TS2322:   Types of property 'sn' are incompatible.
+!!! error TS2322:     Type 'string | number | undefined' is not assignable to type 'string | number'.
+!!! error TS2322:       Type 'undefined' is not assignable to type 'string | number'.
+        let optionalUnionDuplicates: { sn: string | number } = { ...definiteBoolean, ...definiteString, ...optionalString, ...optionalNumber };
+            ~~~~~~~~~~~~~~~~~~~~~~~
+!!! error TS2322: Type '{ sn: string | number | undefined; }' is not assignable to type '{ sn: string | number; }'.
+!!! error TS2322:   Types of property 'sn' are incompatible.
+!!! error TS2322:     Type 'string | number | undefined' is not assignable to type 'string | number'.
+!!! error TS2322:       Type 'undefined' is not assignable to type 'string | number'.
+        let allOptional: { sn?: string | number } = { ...optionalString, ...optionalNumber };
+    
+        // undefined
+        let undefinedUnionStops: { sn: string | number } = { ...definiteBoolean, ...definiteString, ...undefinedNumber };
+            ~~~~~~~~~~~~~~~~~~~
+!!! error TS2322: Type '{ sn: number | undefined; }' is not assignable to type '{ sn: string | number; }'.
+!!! error TS2322:   Types of property 'sn' are incompatible.
+!!! error TS2322:     Type 'number | undefined' is not assignable to type 'string | number'.
+!!! error TS2322:       Type 'undefined' is not assignable to type 'string | number'.
+        let undefinedUnionDuplicates: { sn: string | number } = { ...definiteBoolean, ...definiteString, ...undefinedString, ...undefinedNumber };
+            ~~~~~~~~~~~~~~~~~~~~~~~~
+!!! error TS2322: Type '{ sn: number | undefined; }' is not assignable to type '{ sn: string | number; }'.
+!!! error TS2322:   Types of property 'sn' are incompatible.
+!!! error TS2322:     Type 'number | undefined' is not assignable to type 'string | number'.
+!!! error TS2322:       Type 'undefined' is not assignable to type 'string | number'.
+        let allUndefined: { sn: string | number | undefined } = { ...undefinedString, ...undefinedNumber };
+    
+        let undefinedWithOptionalContinues: { sn: string | number | boolean } = { ...definiteBoolean, ...undefinedString, ...optionalNumber };
+            ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+!!! error TS2322: Type '{ sn: string | number | undefined; }' is not assignable to type '{ sn: string | number | boolean; }'.
+!!! error TS2322:   Types of property 'sn' are incompatible.
+!!! error TS2322:     Type 'string | number | undefined' is not assignable to type 'string | number | boolean'.
+!!! error TS2322:       Type 'undefined' is not assignable to type 'string | number | boolean'.
+    }
+    
+    type Movie = {
+        title: string;
+        yearReleased: number;
+    }
+    
+    const m = { title: "The Matrix", yearReleased: 1999 };
+    // should error here because title: undefined is not assignable to string
+    const x: Movie = { ...m, title: undefined };
+          ~
+!!! error TS2322: Type '{ title: undefined; yearReleased: number; }' is not assignable to type 'Movie'.
+!!! error TS2322:   Types of property 'title' are incompatible.
+!!! error TS2322:     Type 'undefined' is not assignable to type 'string'.
+    
\ No newline at end of file
diff --git a/tests/baselines/reference/objectSpreadStrictNull.js b/tests/baselines/reference/objectSpreadStrictNull.js
index 8a4cf0e5f9fc6..a21b5e2467cc7 100644
--- a/tests/baselines/reference/objectSpreadStrictNull.js
+++ b/tests/baselines/reference/objectSpreadStrictNull.js
@@ -18,6 +18,15 @@ function f(
 
     let undefinedWithOptionalContinues: { sn: string | number | boolean } = { ...definiteBoolean, ...undefinedString, ...optionalNumber };
 }
+
+type Movie = {
+    title: string;
+    yearReleased: number;
+}
+
+const m = { title: "The Matrix", yearReleased: 1999 };
+// should error here because title: undefined is not assignable to string
+const x: Movie = { ...m, title: undefined };
 
 
 //// [objectSpreadStrictNull.js]
@@ -40,3 +49,6 @@ function f(definiteBoolean, definiteString, optionalString, optionalNumber, unde
     var allUndefined = __assign({}, undefinedString, undefinedNumber);
     var undefinedWithOptionalContinues = __assign({}, definiteBoolean, undefinedString, optionalNumber);
 }
+var m = { title: "The Matrix", yearReleased: 1999 };
+// should error here because title: undefined is not assignable to string
+var x = __assign({}, m, { title: undefined });
diff --git a/tests/baselines/reference/objectSpreadStrictNull.symbols b/tests/baselines/reference/objectSpreadStrictNull.symbols
deleted file mode 100644
index e9202767945f8..0000000000000
--- a/tests/baselines/reference/objectSpreadStrictNull.symbols
+++ /dev/null
@@ -1,80 +0,0 @@
-=== tests/cases/conformance/types/spread/objectSpreadStrictNull.ts ===
-function f(
->f : Symbol(f, Decl(objectSpreadStrictNull.ts, 0, 0))
-
-    definiteBoolean: { sn: boolean },
->definiteBoolean : Symbol(definiteBoolean, Decl(objectSpreadStrictNull.ts, 0, 11))
->sn : Symbol(sn, Decl(objectSpreadStrictNull.ts, 1, 22))
-
-    definiteString: { sn: string },
->definiteString : Symbol(definiteString, Decl(objectSpreadStrictNull.ts, 1, 37))
->sn : Symbol(sn, Decl(objectSpreadStrictNull.ts, 2, 21))
-
-    optionalString: { sn?: string },
->optionalString : Symbol(optionalString, Decl(objectSpreadStrictNull.ts, 2, 35))
->sn : Symbol(sn, Decl(objectSpreadStrictNull.ts, 3, 21))
-
-    optionalNumber: { sn?: number },
->optionalNumber : Symbol(optionalNumber, Decl(objectSpreadStrictNull.ts, 3, 36))
->sn : Symbol(sn, Decl(objectSpreadStrictNull.ts, 4, 21))
-
-    undefinedString: { sn: string | undefined },
->undefinedString : Symbol(undefinedString, Decl(objectSpreadStrictNull.ts, 4, 36))
->sn : Symbol(sn, Decl(objectSpreadStrictNull.ts, 5, 22))
-
-    undefinedNumber: { sn: number | undefined }) {
->undefinedNumber : Symbol(undefinedNumber, Decl(objectSpreadStrictNull.ts, 5, 48))
->sn : Symbol(sn, Decl(objectSpreadStrictNull.ts, 6, 22))
-
-    // optional
-    let optionalUnionStops: { sn: string | number } = { ...definiteBoolean, ...definiteString, ...optionalNumber };
->optionalUnionStops : Symbol(optionalUnionStops, Decl(objectSpreadStrictNull.ts, 8, 7))
->sn : Symbol(sn, Decl(objectSpreadStrictNull.ts, 8, 29))
->definiteBoolean : Symbol(definiteBoolean, Decl(objectSpreadStrictNull.ts, 0, 11))
->definiteString : Symbol(definiteString, Decl(objectSpreadStrictNull.ts, 1, 37))
->optionalNumber : Symbol(optionalNumber, Decl(objectSpreadStrictNull.ts, 3, 36))
-
-    let optionalUnionDuplicates: { sn: string | number } = { ...definiteBoolean, ...definiteString, ...optionalString, ...optionalNumber };
->optionalUnionDuplicates : Symbol(optionalUnionDuplicates, Decl(objectSpreadStrictNull.ts, 9, 7))
->sn : Symbol(sn, Decl(objectSpreadStrictNull.ts, 9, 34))
->definiteBoolean : Symbol(definiteBoolean, Decl(objectSpreadStrictNull.ts, 0, 11))
->definiteString : Symbol(definiteString, Decl(objectSpreadStrictNull.ts, 1, 37))
->optionalString : Symbol(optionalString, Decl(objectSpreadStrictNull.ts, 2, 35))
->optionalNumber : Symbol(optionalNumber, Decl(objectSpreadStrictNull.ts, 3, 36))
-
-    let allOptional: { sn?: string | number } = { ...optionalString, ...optionalNumber };
->allOptional : Symbol(allOptional, Decl(objectSpreadStrictNull.ts, 10, 7))
->sn : Symbol(sn, Decl(objectSpreadStrictNull.ts, 10, 22))
->optionalString : Symbol(optionalString, Decl(objectSpreadStrictNull.ts, 2, 35))
->optionalNumber : Symbol(optionalNumber, Decl(objectSpreadStrictNull.ts, 3, 36))
-
-    // undefined
-    let undefinedUnionStops: { sn: string | number } = { ...definiteBoolean, ...definiteString, ...undefinedNumber };
->undefinedUnionStops : Symbol(undefinedUnionStops, Decl(objectSpreadStrictNull.ts, 13, 7))
->sn : Symbol(sn, Decl(objectSpreadStrictNull.ts, 13, 30))
->definiteBoolean : Symbol(definiteBoolean, Decl(objectSpreadStrictNull.ts, 0, 11))
->definiteString : Symbol(definiteString, Decl(objectSpreadStrictNull.ts, 1, 37))
->undefinedNumber : Symbol(undefinedNumber, Decl(objectSpreadStrictNull.ts, 5, 48))
-
-    let undefinedUnionDuplicates: { sn: string | number } = { ...definiteBoolean, ...definiteString, ...undefinedString, ...undefinedNumber };
->undefinedUnionDuplicates : Symbol(undefinedUnionDuplicates, Decl(objectSpreadStrictNull.ts, 14, 7))
->sn : Symbol(sn, Decl(objectSpreadStrictNull.ts, 14, 35))
->definiteBoolean : Symbol(definiteBoolean, Decl(objectSpreadStrictNull.ts, 0, 11))
->definiteString : Symbol(definiteString, Decl(objectSpreadStrictNull.ts, 1, 37))
->undefinedString : Symbol(undefinedString, Decl(objectSpreadStrictNull.ts, 4, 36))
->undefinedNumber : Symbol(undefinedNumber, Decl(objectSpreadStrictNull.ts, 5, 48))
-
-    let allUndefined: { sn: string | number | undefined } = { ...undefinedString, ...undefinedNumber };
->allUndefined : Symbol(allUndefined, Decl(objectSpreadStrictNull.ts, 15, 7))
->sn : Symbol(sn, Decl(objectSpreadStrictNull.ts, 15, 23))
->undefinedString : Symbol(undefinedString, Decl(objectSpreadStrictNull.ts, 4, 36))
->undefinedNumber : Symbol(undefinedNumber, Decl(objectSpreadStrictNull.ts, 5, 48))
-
-    let undefinedWithOptionalContinues: { sn: string | number | boolean } = { ...definiteBoolean, ...undefinedString, ...optionalNumber };
->undefinedWithOptionalContinues : Symbol(undefinedWithOptionalContinues, Decl(objectSpreadStrictNull.ts, 17, 7))
->sn : Symbol(sn, Decl(objectSpreadStrictNull.ts, 17, 41))
->definiteBoolean : Symbol(definiteBoolean, Decl(objectSpreadStrictNull.ts, 0, 11))
->undefinedString : Symbol(undefinedString, Decl(objectSpreadStrictNull.ts, 4, 36))
->optionalNumber : Symbol(optionalNumber, Decl(objectSpreadStrictNull.ts, 3, 36))
-}
-
diff --git a/tests/baselines/reference/objectSpreadStrictNull.types b/tests/baselines/reference/objectSpreadStrictNull.types
deleted file mode 100644
index f70f0a9cad26c..0000000000000
--- a/tests/baselines/reference/objectSpreadStrictNull.types
+++ /dev/null
@@ -1,87 +0,0 @@
-=== tests/cases/conformance/types/spread/objectSpreadStrictNull.ts ===
-function f(
->f : (definiteBoolean: { sn: boolean; }, definiteString: { sn: string; }, optionalString: { sn?: string | undefined; }, optionalNumber: { sn?: number | undefined; }, undefinedString: { sn: string | undefined; }, undefinedNumber: { sn: number | undefined; }) => void
-
-    definiteBoolean: { sn: boolean },
->definiteBoolean : { sn: boolean; }
->sn : boolean
-
-    definiteString: { sn: string },
->definiteString : { sn: string; }
->sn : string
-
-    optionalString: { sn?: string },
->optionalString : { sn?: string | undefined; }
->sn : string | undefined
-
-    optionalNumber: { sn?: number },
->optionalNumber : { sn?: number | undefined; }
->sn : number | undefined
-
-    undefinedString: { sn: string | undefined },
->undefinedString : { sn: string | undefined; }
->sn : string | undefined
-
-    undefinedNumber: { sn: number | undefined }) {
->undefinedNumber : { sn: number | undefined; }
->sn : number | undefined
-
-    // optional
-    let optionalUnionStops: { sn: string | number } = { ...definiteBoolean, ...definiteString, ...optionalNumber };
->optionalUnionStops : { sn: string | number; }
->sn : string | number
->{ ...definiteBoolean, ...definiteString, ...optionalNumber } : { sn: string | number; }
->definiteBoolean : { sn: boolean; }
->definiteString : { sn: string; }
->optionalNumber : { sn?: number | undefined; }
-
-    let optionalUnionDuplicates: { sn: string | number } = { ...definiteBoolean, ...definiteString, ...optionalString, ...optionalNumber };
->optionalUnionDuplicates : { sn: string | number; }
->sn : string | number
->{ ...definiteBoolean, ...definiteString, ...optionalString, ...optionalNumber } : { sn: string | number; }
->definiteBoolean : { sn: boolean; }
->definiteString : { sn: string; }
->optionalString : { sn?: string | undefined; }
->optionalNumber : { sn?: number | undefined; }
-
-    let allOptional: { sn?: string | number } = { ...optionalString, ...optionalNumber };
->allOptional : { sn?: string | number | undefined; }
->sn : string | number | undefined
->{ ...optionalString, ...optionalNumber } : { sn?: string | number | undefined; }
->optionalString : { sn?: string | undefined; }
->optionalNumber : { sn?: number | undefined; }
-
-    // undefined
-    let undefinedUnionStops: { sn: string | number } = { ...definiteBoolean, ...definiteString, ...undefinedNumber };
->undefinedUnionStops : { sn: string | number; }
->sn : string | number
->{ ...definiteBoolean, ...definiteString, ...undefinedNumber } : { sn: string | number; }
->definiteBoolean : { sn: boolean; }
->definiteString : { sn: string; }
->undefinedNumber : { sn: number | undefined; }
-
-    let undefinedUnionDuplicates: { sn: string | number } = { ...definiteBoolean, ...definiteString, ...undefinedString, ...undefinedNumber };
->undefinedUnionDuplicates : { sn: string | number; }
->sn : string | number
->{ ...definiteBoolean, ...definiteString, ...undefinedString, ...undefinedNumber } : { sn: string | number; }
->definiteBoolean : { sn: boolean; }
->definiteString : { sn: string; }
->undefinedString : { sn: string | undefined; }
->undefinedNumber : { sn: number | undefined; }
-
-    let allUndefined: { sn: string | number | undefined } = { ...undefinedString, ...undefinedNumber };
->allUndefined : { sn: string | number | undefined; }
->sn : string | number | undefined
->{ ...undefinedString, ...undefinedNumber } : { sn: string | number | undefined; }
->undefinedString : { sn: string | undefined; }
->undefinedNumber : { sn: number | undefined; }
-
-    let undefinedWithOptionalContinues: { sn: string | number | boolean } = { ...definiteBoolean, ...undefinedString, ...optionalNumber };
->undefinedWithOptionalContinues : { sn: string | number | boolean; }
->sn : string | number | boolean
->{ ...definiteBoolean, ...undefinedString, ...optionalNumber } : { sn: string | number | boolean; }
->definiteBoolean : { sn: boolean; }
->undefinedString : { sn: string | undefined; }
->optionalNumber : { sn?: number | undefined; }
-}
-
diff --git a/tests/cases/conformance/types/spread/objectSpreadStrictNull.ts b/tests/cases/conformance/types/spread/objectSpreadStrictNull.ts
index 087d47df26c35..979a6feed03bd 100644
--- a/tests/cases/conformance/types/spread/objectSpreadStrictNull.ts
+++ b/tests/cases/conformance/types/spread/objectSpreadStrictNull.ts
@@ -19,3 +19,12 @@ function f(
 
     let undefinedWithOptionalContinues: { sn: string | number | boolean } = { ...definiteBoolean, ...undefinedString, ...optionalNumber };
 }
+
+type Movie = {
+    title: string;
+    yearReleased: number;
+}
+
+const m = { title: "The Matrix", yearReleased: 1999 };
+// should error here because title: undefined is not assignable to string
+const x: Movie = { ...m, title: undefined };