diff --git a/lib/tsc.js b/lib/tsc.js
index 2be63c051ad..99e4d75cbf7 100644
--- a/lib/tsc.js
+++ b/lib/tsc.js
@@ -4271,10 +4271,13 @@ var ts;
             (node.name.kind === 9 || isGlobalScopeAugmentation(node));
     }
     ts.isAmbientModule = isAmbientModule;
+    function isShorthandAmbientModuleSymbol(moduleSymbol) {
+        return isShorthandAmbientModule(moduleSymbol.valueDeclaration);
+    }
+    ts.isShorthandAmbientModuleSymbol = isShorthandAmbientModuleSymbol;
     function isShorthandAmbientModule(node) {
         return node.kind === 225 && (!node.body);
     }
-    ts.isShorthandAmbientModule = isShorthandAmbientModule;
     function isBlockScopedContainerTopLevel(node) {
         return node.kind === 256 ||
             node.kind === 225 ||
@@ -13944,7 +13947,7 @@ var ts;
         function getTargetOfImportClause(node) {
             var moduleSymbol = resolveExternalModuleName(node, node.parent.moduleSpecifier);
             if (moduleSymbol) {
-                var exportDefaultSymbol = ts.isShorthandAmbientModule(moduleSymbol.valueDeclaration) ?
+                var exportDefaultSymbol = ts.isShorthandAmbientModuleSymbol(moduleSymbol) ?
                     moduleSymbol :
                     moduleSymbol.exports["export="] ?
                         getPropertyOfType(getTypeOfSymbol(moduleSymbol.exports["export="]), "default") :
@@ -13999,7 +14002,7 @@ var ts;
             if (targetSymbol) {
                 var name_10 = specifier.propertyName || specifier.name;
                 if (name_10.text) {
-                    if (ts.isShorthandAmbientModule(moduleSymbol.valueDeclaration)) {
+                    if (ts.isShorthandAmbientModuleSymbol(moduleSymbol)) {
                         return moduleSymbol;
                     }
                     var symbolFromVariable = void 0;
@@ -15774,7 +15777,7 @@ var ts;
         function getTypeOfFuncClassEnumModule(symbol) {
             var links = getSymbolLinks(symbol);
             if (!links.type) {
-                if (symbol.valueDeclaration.kind === 225 && ts.isShorthandAmbientModule(symbol.valueDeclaration)) {
+                if (symbol.valueDeclaration.kind === 225 && ts.isShorthandAmbientModuleSymbol(symbol)) {
                     links.type = anyType;
                 }
                 else {
@@ -20167,7 +20170,7 @@ var ts;
                     }
                 }
                 var targetType = type.flags & 16384 ? getApparentType(type) : type;
-                return isTypeSubtypeOf(candidate, targetType) ? candidate :
+                return isTypeSubtypeOf(candidate, type) ? candidate :
                     isTypeAssignableTo(type, candidate) ? type :
                         isTypeAssignableTo(candidate, targetType) ? candidate :
                             getIntersectionType([type, candidate]);
@@ -27123,7 +27126,7 @@ var ts;
         }
         function moduleExportsSomeValue(moduleReferenceExpression) {
             var moduleSymbol = resolveExternalModuleName(moduleReferenceExpression.parent, moduleReferenceExpression);
-            if (!moduleSymbol) {
+            if (!moduleSymbol || ts.isShorthandAmbientModuleSymbol(moduleSymbol)) {
                 return true;
             }
             var hasExportAssignment = hasExportAssignmentSymbol(moduleSymbol);
diff --git a/lib/tsserver.js b/lib/tsserver.js
index 94b94d71415..ea61f48883c 100644
--- a/lib/tsserver.js
+++ b/lib/tsserver.js
@@ -5267,10 +5267,13 @@ var ts;
             (node.name.kind === 9 || isGlobalScopeAugmentation(node));
     }
     ts.isAmbientModule = isAmbientModule;
+    function isShorthandAmbientModuleSymbol(moduleSymbol) {
+        return isShorthandAmbientModule(moduleSymbol.valueDeclaration);
+    }
+    ts.isShorthandAmbientModuleSymbol = isShorthandAmbientModuleSymbol;
     function isShorthandAmbientModule(node) {
         return node.kind === 225 && (!node.body);
     }
-    ts.isShorthandAmbientModule = isShorthandAmbientModule;
     function isBlockScopedContainerTopLevel(node) {
         return node.kind === 256 ||
             node.kind === 225 ||
@@ -14940,7 +14943,7 @@ var ts;
         function getTargetOfImportClause(node) {
             var moduleSymbol = resolveExternalModuleName(node, node.parent.moduleSpecifier);
             if (moduleSymbol) {
-                var exportDefaultSymbol = ts.isShorthandAmbientModule(moduleSymbol.valueDeclaration) ?
+                var exportDefaultSymbol = ts.isShorthandAmbientModuleSymbol(moduleSymbol) ?
                     moduleSymbol :
                     moduleSymbol.exports["export="] ?
                         getPropertyOfType(getTypeOfSymbol(moduleSymbol.exports["export="]), "default") :
@@ -14995,7 +14998,7 @@ var ts;
             if (targetSymbol) {
                 var name_12 = specifier.propertyName || specifier.name;
                 if (name_12.text) {
-                    if (ts.isShorthandAmbientModule(moduleSymbol.valueDeclaration)) {
+                    if (ts.isShorthandAmbientModuleSymbol(moduleSymbol)) {
                         return moduleSymbol;
                     }
                     var symbolFromVariable = void 0;
@@ -16770,7 +16773,7 @@ var ts;
         function getTypeOfFuncClassEnumModule(symbol) {
             var links = getSymbolLinks(symbol);
             if (!links.type) {
-                if (symbol.valueDeclaration.kind === 225 && ts.isShorthandAmbientModule(symbol.valueDeclaration)) {
+                if (symbol.valueDeclaration.kind === 225 && ts.isShorthandAmbientModuleSymbol(symbol)) {
                     links.type = anyType;
                 }
                 else {
@@ -21163,7 +21166,7 @@ var ts;
                     }
                 }
                 var targetType = type.flags & 16384 ? getApparentType(type) : type;
-                return isTypeSubtypeOf(candidate, targetType) ? candidate :
+                return isTypeSubtypeOf(candidate, type) ? candidate :
                     isTypeAssignableTo(type, candidate) ? type :
                         isTypeAssignableTo(candidate, targetType) ? candidate :
                             getIntersectionType([type, candidate]);
@@ -28119,7 +28122,7 @@ var ts;
         }
         function moduleExportsSomeValue(moduleReferenceExpression) {
             var moduleSymbol = resolveExternalModuleName(moduleReferenceExpression.parent, moduleReferenceExpression);
-            if (!moduleSymbol) {
+            if (!moduleSymbol || ts.isShorthandAmbientModuleSymbol(moduleSymbol)) {
                 return true;
             }
             var hasExportAssignment = hasExportAssignmentSymbol(moduleSymbol);
diff --git a/lib/tsserverlibrary.d.ts b/lib/tsserverlibrary.d.ts
index 7fe9da64cfe..c7ca800d0fe 100644
--- a/lib/tsserverlibrary.d.ts
+++ b/lib/tsserverlibrary.d.ts
@@ -7043,7 +7043,7 @@ declare namespace ts {
     function makeIdentifierFromModuleName(moduleName: string): string;
     function isBlockOrCatchScoped(declaration: Declaration): boolean;
     function isAmbientModule(node: Node): boolean;
-    function isShorthandAmbientModule(node: Node): boolean;
+    function isShorthandAmbientModuleSymbol(moduleSymbol: Symbol): boolean;
     function isBlockScopedContainerTopLevel(node: Node): boolean;
     function isGlobalScopeAugmentation(module: ModuleDeclaration): boolean;
     function isExternalModuleAugmentation(node: Node): boolean;
diff --git a/lib/tsserverlibrary.js b/lib/tsserverlibrary.js
index 724a16dd326..88edc5dce20 100644
--- a/lib/tsserverlibrary.js
+++ b/lib/tsserverlibrary.js
@@ -5267,10 +5267,13 @@ var ts;
             (node.name.kind === 9 || isGlobalScopeAugmentation(node));
     }
     ts.isAmbientModule = isAmbientModule;
+    function isShorthandAmbientModuleSymbol(moduleSymbol) {
+        return isShorthandAmbientModule(moduleSymbol.valueDeclaration);
+    }
+    ts.isShorthandAmbientModuleSymbol = isShorthandAmbientModuleSymbol;
     function isShorthandAmbientModule(node) {
         return node.kind === 225 && (!node.body);
     }
-    ts.isShorthandAmbientModule = isShorthandAmbientModule;
     function isBlockScopedContainerTopLevel(node) {
         return node.kind === 256 ||
             node.kind === 225 ||
@@ -14940,7 +14943,7 @@ var ts;
         function getTargetOfImportClause(node) {
             var moduleSymbol = resolveExternalModuleName(node, node.parent.moduleSpecifier);
             if (moduleSymbol) {
-                var exportDefaultSymbol = ts.isShorthandAmbientModule(moduleSymbol.valueDeclaration) ?
+                var exportDefaultSymbol = ts.isShorthandAmbientModuleSymbol(moduleSymbol) ?
                     moduleSymbol :
                     moduleSymbol.exports["export="] ?
                         getPropertyOfType(getTypeOfSymbol(moduleSymbol.exports["export="]), "default") :
@@ -14995,7 +14998,7 @@ var ts;
             if (targetSymbol) {
                 var name_12 = specifier.propertyName || specifier.name;
                 if (name_12.text) {
-                    if (ts.isShorthandAmbientModule(moduleSymbol.valueDeclaration)) {
+                    if (ts.isShorthandAmbientModuleSymbol(moduleSymbol)) {
                         return moduleSymbol;
                     }
                     var symbolFromVariable = void 0;
@@ -16770,7 +16773,7 @@ var ts;
         function getTypeOfFuncClassEnumModule(symbol) {
             var links = getSymbolLinks(symbol);
             if (!links.type) {
-                if (symbol.valueDeclaration.kind === 225 && ts.isShorthandAmbientModule(symbol.valueDeclaration)) {
+                if (symbol.valueDeclaration.kind === 225 && ts.isShorthandAmbientModuleSymbol(symbol)) {
                     links.type = anyType;
                 }
                 else {
@@ -21163,7 +21166,7 @@ var ts;
                     }
                 }
                 var targetType = type.flags & 16384 ? getApparentType(type) : type;
-                return isTypeSubtypeOf(candidate, targetType) ? candidate :
+                return isTypeSubtypeOf(candidate, type) ? candidate :
                     isTypeAssignableTo(type, candidate) ? type :
                         isTypeAssignableTo(candidate, targetType) ? candidate :
                             getIntersectionType([type, candidate]);
@@ -28119,7 +28122,7 @@ var ts;
         }
         function moduleExportsSomeValue(moduleReferenceExpression) {
             var moduleSymbol = resolveExternalModuleName(moduleReferenceExpression.parent, moduleReferenceExpression);
-            if (!moduleSymbol) {
+            if (!moduleSymbol || ts.isShorthandAmbientModuleSymbol(moduleSymbol)) {
                 return true;
             }
             var hasExportAssignment = hasExportAssignmentSymbol(moduleSymbol);
diff --git a/lib/typescript.js b/lib/typescript.js
index b4f5deb40a0..d3b32c17496 100644
--- a/lib/typescript.js
+++ b/lib/typescript.js
@@ -5636,11 +5636,14 @@ var ts;
             (node.name.kind === 9 /* StringLiteral */ || isGlobalScopeAugmentation(node));
     }
     ts.isAmbientModule = isAmbientModule;
+    function isShorthandAmbientModuleSymbol(moduleSymbol) {
+        return isShorthandAmbientModule(moduleSymbol.valueDeclaration);
+    }
+    ts.isShorthandAmbientModuleSymbol = isShorthandAmbientModuleSymbol;
     function isShorthandAmbientModule(node) {
         // The only kind of module that can be missing a body is a shorthand ambient module.
         return node.kind === 225 /* ModuleDeclaration */ && (!node.body);
     }
-    ts.isShorthandAmbientModule = isShorthandAmbientModule;
     function isBlockScopedContainerTopLevel(node) {
         return node.kind === 256 /* SourceFile */ ||
             node.kind === 225 /* ModuleDeclaration */ ||
@@ -17445,7 +17448,7 @@ var ts;
         function getTargetOfImportClause(node) {
             var moduleSymbol = resolveExternalModuleName(node, node.parent.moduleSpecifier);
             if (moduleSymbol) {
-                var exportDefaultSymbol = ts.isShorthandAmbientModule(moduleSymbol.valueDeclaration) ?
+                var exportDefaultSymbol = ts.isShorthandAmbientModuleSymbol(moduleSymbol) ?
                     moduleSymbol :
                     moduleSymbol.exports["export="] ?
                         getPropertyOfType(getTypeOfSymbol(moduleSymbol.exports["export="]), "default") :
@@ -17518,7 +17521,7 @@ var ts;
             if (targetSymbol) {
                 var name_10 = specifier.propertyName || specifier.name;
                 if (name_10.text) {
-                    if (ts.isShorthandAmbientModule(moduleSymbol.valueDeclaration)) {
+                    if (ts.isShorthandAmbientModuleSymbol(moduleSymbol)) {
                         return moduleSymbol;
                     }
                     var symbolFromVariable = void 0;
@@ -19549,7 +19552,7 @@ var ts;
         function getTypeOfFuncClassEnumModule(symbol) {
             var links = getSymbolLinks(symbol);
             if (!links.type) {
-                if (symbol.valueDeclaration.kind === 225 /* ModuleDeclaration */ && ts.isShorthandAmbientModule(symbol.valueDeclaration)) {
+                if (symbol.valueDeclaration.kind === 225 /* ModuleDeclaration */ && ts.isShorthandAmbientModuleSymbol(symbol)) {
                     links.type = anyType;
                 }
                 else {
@@ -24454,7 +24457,7 @@ var ts;
                 // type. Otherwise, the types are completely unrelated, so narrow to an intersection of the
                 // two types.
                 var targetType = type.flags & 16384 /* TypeParameter */ ? getApparentType(type) : type;
-                return isTypeSubtypeOf(candidate, targetType) ? candidate :
+                return isTypeSubtypeOf(candidate, type) ? candidate :
                     isTypeAssignableTo(type, candidate) ? type :
                         isTypeAssignableTo(candidate, targetType) ? candidate :
                             getIntersectionType([type, candidate]);
@@ -33082,8 +33085,8 @@ var ts;
         }
         function moduleExportsSomeValue(moduleReferenceExpression) {
             var moduleSymbol = resolveExternalModuleName(moduleReferenceExpression.parent, moduleReferenceExpression);
-            if (!moduleSymbol) {
-                // module not found - be conservative
+            if (!moduleSymbol || ts.isShorthandAmbientModuleSymbol(moduleSymbol)) {
+                // If the module is not found or is shorthand, assume that it may export a value.
                 return true;
             }
             var hasExportAssignment = hasExportAssignmentSymbol(moduleSymbol);
diff --git a/lib/typescriptServices.js b/lib/typescriptServices.js
index b4f5deb40a0..d3b32c17496 100644
--- a/lib/typescriptServices.js
+++ b/lib/typescriptServices.js
@@ -5636,11 +5636,14 @@ var ts;
             (node.name.kind === 9 /* StringLiteral */ || isGlobalScopeAugmentation(node));
     }
     ts.isAmbientModule = isAmbientModule;
+    function isShorthandAmbientModuleSymbol(moduleSymbol) {
+        return isShorthandAmbientModule(moduleSymbol.valueDeclaration);
+    }
+    ts.isShorthandAmbientModuleSymbol = isShorthandAmbientModuleSymbol;
     function isShorthandAmbientModule(node) {
         // The only kind of module that can be missing a body is a shorthand ambient module.
         return node.kind === 225 /* ModuleDeclaration */ && (!node.body);
     }
-    ts.isShorthandAmbientModule = isShorthandAmbientModule;
     function isBlockScopedContainerTopLevel(node) {
         return node.kind === 256 /* SourceFile */ ||
             node.kind === 225 /* ModuleDeclaration */ ||
@@ -17445,7 +17448,7 @@ var ts;
         function getTargetOfImportClause(node) {
             var moduleSymbol = resolveExternalModuleName(node, node.parent.moduleSpecifier);
             if (moduleSymbol) {
-                var exportDefaultSymbol = ts.isShorthandAmbientModule(moduleSymbol.valueDeclaration) ?
+                var exportDefaultSymbol = ts.isShorthandAmbientModuleSymbol(moduleSymbol) ?
                     moduleSymbol :
                     moduleSymbol.exports["export="] ?
                         getPropertyOfType(getTypeOfSymbol(moduleSymbol.exports["export="]), "default") :
@@ -17518,7 +17521,7 @@ var ts;
             if (targetSymbol) {
                 var name_10 = specifier.propertyName || specifier.name;
                 if (name_10.text) {
-                    if (ts.isShorthandAmbientModule(moduleSymbol.valueDeclaration)) {
+                    if (ts.isShorthandAmbientModuleSymbol(moduleSymbol)) {
                         return moduleSymbol;
                     }
                     var symbolFromVariable = void 0;
@@ -19549,7 +19552,7 @@ var ts;
         function getTypeOfFuncClassEnumModule(symbol) {
             var links = getSymbolLinks(symbol);
             if (!links.type) {
-                if (symbol.valueDeclaration.kind === 225 /* ModuleDeclaration */ && ts.isShorthandAmbientModule(symbol.valueDeclaration)) {
+                if (symbol.valueDeclaration.kind === 225 /* ModuleDeclaration */ && ts.isShorthandAmbientModuleSymbol(symbol)) {
                     links.type = anyType;
                 }
                 else {
@@ -24454,7 +24457,7 @@ var ts;
                 // type. Otherwise, the types are completely unrelated, so narrow to an intersection of the
                 // two types.
                 var targetType = type.flags & 16384 /* TypeParameter */ ? getApparentType(type) : type;
-                return isTypeSubtypeOf(candidate, targetType) ? candidate :
+                return isTypeSubtypeOf(candidate, type) ? candidate :
                     isTypeAssignableTo(type, candidate) ? type :
                         isTypeAssignableTo(candidate, targetType) ? candidate :
                             getIntersectionType([type, candidate]);
@@ -33082,8 +33085,8 @@ var ts;
         }
         function moduleExportsSomeValue(moduleReferenceExpression) {
             var moduleSymbol = resolveExternalModuleName(moduleReferenceExpression.parent, moduleReferenceExpression);
-            if (!moduleSymbol) {
-                // module not found - be conservative
+            if (!moduleSymbol || ts.isShorthandAmbientModuleSymbol(moduleSymbol)) {
+                // If the module is not found or is shorthand, assume that it may export a value.
                 return true;
             }
             var hasExportAssignment = hasExportAssignmentSymbol(moduleSymbol);