diff --git a/src/compiler/checker.ts b/src/compiler/checker.ts
index e43001ec43..c25ec01fbf 100644
--- a/src/compiler/checker.ts
+++ b/src/compiler/checker.ts
@@ -9352,7 +9352,10 @@ namespace ts {
                                 }
                                 return Ternary.False;
                             }
+                            const saveDisableWeakTypeErrors = disableWeakTypeErrors;
+                            disableWeakTypeErrors = false;
                             const related = isRelatedTo(getTypeOfSymbol(sourceProp), getTypeOfSymbol(targetProp), reportErrors);
+                            disableWeakTypeErrors = saveDisableWeakTypeErrors;
                             if (!related) {
                                 if (reportErrors) {
                                     reportError(Diagnostics.Types_of_property_0_are_incompatible, symbolToString(targetProp));
diff --git a/tests/baselines/reference/weakType.errors.txt b/tests/baselines/reference/weakType.errors.txt
index 8d0da84859..432f3dfd8e 100644
--- a/tests/baselines/reference/weakType.errors.txt
+++ b/tests/baselines/reference/weakType.errors.txt
@@ -1,8 +1,13 @@
 tests/cases/compiler/weakType.ts(31,18): error TS2345: Argument of type '{ error?: number; }' is not assignable to parameter of type 'ChangeOptions'.
   Weak type 'ChangeOptions' has no properties in common with '{ error?: number; }'.
+tests/cases/compiler/weakType.ts(56,5): error TS2322: Type '{ properties: { wrong: string; }; }' is not assignable to type 'Weak & Spoiler'.
+  Type '{ properties: { wrong: string; }; }' is not assignable to type 'Weak'.
+    Types of property 'properties' are incompatible.
+      Type '{ wrong: string; }' is not assignable to type '{ b?: number; }'.
+        Weak type '{ b?: number; }' has no properties in common with '{ wrong: string; }'.
 
 
-==== tests/cases/compiler/weakType.ts (1 errors) ====
+==== tests/cases/compiler/weakType.ts (2 errors) ====
     interface Settings {
         timeout?: number;
         onError?(): void;
@@ -48,4 +53,24 @@ tests/cases/compiler/weakType.ts(31,18): error TS2345: Argument of type '{ error
         n?: number
     }
     let ctor: Ctor = K
+    
+    type Spoiler = { nope?: string }
+    type Weak = {
+        a?: number
+        properties?: {
+            b?: number
+        }
+    }
+    declare let unknown: {
+        properties: {
+            wrong: string
+        }
+    }
+    let weak: Weak & Spoiler = unknown
+        ~~~~
+!!! error TS2322: Type '{ properties: { wrong: string; }; }' is not assignable to type 'Weak & Spoiler'.
+!!! error TS2322:   Type '{ properties: { wrong: string; }; }' is not assignable to type 'Weak'.
+!!! error TS2322:     Types of property 'properties' are incompatible.
+!!! error TS2322:       Type '{ wrong: string; }' is not assignable to type '{ b?: number; }'.
+!!! error TS2322:         Weak type '{ b?: number; }' has no properties in common with '{ wrong: string; }'.
     
\ No newline at end of file
diff --git a/tests/baselines/reference/weakType.js b/tests/baselines/reference/weakType.js
index 365b45d68c..6ed3ff1814 100644
--- a/tests/baselines/reference/weakType.js
+++ b/tests/baselines/reference/weakType.js
@@ -41,6 +41,20 @@ interface Ctor {
     n?: number
 }
 let ctor: Ctor = K
+
+type Spoiler = { nope?: string }
+type Weak = {
+    a?: number
+    properties?: {
+        b?: number
+    }
+}
+declare let unknown: {
+    properties: {
+        wrong: string
+    }
+}
+let weak: Weak & Spoiler = unknown
 
 
 //// [weakType.js]
@@ -64,3 +78,4 @@ var K = (function () {
     return K;
 }());
 var ctor = K;
+var weak = unknown;
diff --git a/tests/cases/compiler/weakType.ts b/tests/cases/compiler/weakType.ts
index a1d1cae7f6..f04f36c9c2 100644
--- a/tests/cases/compiler/weakType.ts
+++ b/tests/cases/compiler/weakType.ts
@@ -40,3 +40,17 @@ interface Ctor {
     n?: number
 }
 let ctor: Ctor = K
+
+type Spoiler = { nope?: string }
+type Weak = {
+    a?: number
+    properties?: {
+        b?: number
+    }
+}
+declare let unknown: {
+    properties: {
+        wrong: string
+    }
+}
+let weak: Weak & Spoiler = unknown