diff --git a/include/swift/IDE/DigesterEnums.def b/include/swift/IDE/DigesterEnums.def
index f730523e4b6..53dae114e51 100644
--- a/include/swift/IDE/DigesterEnums.def
+++ b/include/swift/IDE/DigesterEnums.def
@@ -45,6 +45,7 @@ NODE_KIND(DeclGetter, Getter)
 NODE_KIND(DeclSetter, Setter)
 NODE_KIND(DeclVar, Var)
 NODE_KIND(DeclTypeAlias, TypeAlias)
+NODE_KIND(DeclAssociatedType, AssociatedType)
 
 NODE_ANNOTATION(Added)
 NODE_ANNOTATION(Removed)
diff --git a/test/api-digester/Inputs/cake.swift b/test/api-digester/Inputs/cake.swift
index ea09c0a9f6a..d86173ab82f 100644
--- a/test/api-digester/Inputs/cake.swift
+++ b/test/api-digester/Inputs/cake.swift
@@ -49,4 +49,9 @@ public struct fixedLayoutStruct {
   var c = 3
 }
 
-extension Int: P1 { public func bar() {} }
\ No newline at end of file
+extension Int: P1 { public func bar() {} }
+
+public protocol ProWithAssociatedType {
+  associatedtype A
+  associatedtype B = Int
+}
\ No newline at end of file
diff --git a/test/api-digester/Outputs/cake-abi.json b/test/api-digester/Outputs/cake-abi.json
index 93d20c39811..424df9d65ea 100644
--- a/test/api-digester/Outputs/cake-abi.json
+++ b/test/api-digester/Outputs/cake-abi.json
@@ -963,6 +963,43 @@
         }
       ]
     },
+    {
+      "kind": "TypeDecl",
+      "name": "ProWithAssociatedType",
+      "printedName": "ProWithAssociatedType",
+      "declKind": "Protocol",
+      "usr": "s:4cake21ProWithAssociatedTypeP",
+      "location": "",
+      "moduleName": "cake",
+      "children": [
+        {
+          "kind": "AssociatedType",
+          "name": "A",
+          "printedName": "A",
+          "declKind": "AssociatedType",
+          "usr": "s:4cake21ProWithAssociatedTypeP1AQa",
+          "location": "",
+          "moduleName": "cake"
+        },
+        {
+          "kind": "AssociatedType",
+          "name": "B",
+          "printedName": "B",
+          "declKind": "AssociatedType",
+          "usr": "s:4cake21ProWithAssociatedTypeP1BQa",
+          "location": "",
+          "moduleName": "cake",
+          "children": [
+            {
+              "kind": "TypeNominal",
+              "name": "Int",
+              "printedName": "Int",
+              "usr": "s:Si"
+            }
+          ]
+        }
+      ]
+    },
     {
       "kind": "TypeDecl",
       "name": "Int",
diff --git a/test/api-digester/Outputs/cake.json b/test/api-digester/Outputs/cake.json
index cf77baec269..625f0bdab7d 100644
--- a/test/api-digester/Outputs/cake.json
+++ b/test/api-digester/Outputs/cake.json
@@ -839,6 +839,43 @@
         }
       ]
     },
+    {
+      "kind": "TypeDecl",
+      "name": "ProWithAssociatedType",
+      "printedName": "ProWithAssociatedType",
+      "declKind": "Protocol",
+      "usr": "s:4cake21ProWithAssociatedTypeP",
+      "location": "",
+      "moduleName": "cake",
+      "children": [
+        {
+          "kind": "AssociatedType",
+          "name": "A",
+          "printedName": "A",
+          "declKind": "AssociatedType",
+          "usr": "s:4cake21ProWithAssociatedTypeP1AQa",
+          "location": "",
+          "moduleName": "cake"
+        },
+        {
+          "kind": "AssociatedType",
+          "name": "B",
+          "printedName": "B",
+          "declKind": "AssociatedType",
+          "usr": "s:4cake21ProWithAssociatedTypeP1BQa",
+          "location": "",
+          "moduleName": "cake",
+          "children": [
+            {
+              "kind": "TypeNominal",
+              "name": "Int",
+              "printedName": "Int",
+              "usr": "s:Si"
+            }
+          ]
+        }
+      ]
+    },
     {
       "kind": "TypeDecl",
       "name": "Int",
diff --git a/tools/swift-api-digester/ModuleAnalyzerNodes.cpp b/tools/swift-api-digester/ModuleAnalyzerNodes.cpp
index d4f9a4d3158..4d3f3f417f2 100644
--- a/tools/swift-api-digester/ModuleAnalyzerNodes.cpp
+++ b/tools/swift-api-digester/ModuleAnalyzerNodes.cpp
@@ -130,6 +130,9 @@ SDKNodeDeclGetter::SDKNodeDeclGetter(SDKNodeInitInfo Info):
 SDKNodeDeclSetter::SDKNodeDeclSetter(SDKNodeInitInfo Info):
   SDKNodeDeclAbstractFunc(Info, SDKNodeKind::DeclSetter) {}
 
+SDKNodeDeclAssociatedType::SDKNodeDeclAssociatedType(SDKNodeInitInfo Info):
+  SDKNodeDecl(Info, SDKNodeKind::DeclAssociatedType) {};
+
 StringRef SDKNodeDecl::getHeaderName() const {
   if (Location.empty())
     return StringRef();
@@ -348,6 +351,7 @@ bool SDKNodeDecl::classof(const SDKNode *N) {
     case SDKNodeKind::DeclTypeAlias:
     case SDKNodeKind::DeclType:
     case SDKNodeKind::DeclVar:
+    case SDKNodeKind::DeclAssociatedType:
       return true;
     case SDKNodeKind::Root:
     case SDKNodeKind::TypeNominal:
@@ -731,6 +735,7 @@ bool SDKNode::operator==(const SDKNode &Other) const {
       }
       LLVM_FALLTHROUGH;
     }
+    case SDKNodeKind::DeclAssociatedType:
     case SDKNodeKind::DeclTypeAlias: {
       auto Left = this->getAs<SDKNodeDecl>();
       auto Right = (&Other)->getAs<SDKNodeDecl>();
@@ -1250,6 +1255,16 @@ static SDKNode *constructTypeAliasNode(SDKContext &Ctx,TypeAliasDecl *TAD) {
   return Alias;
 }
 
+static SDKNode *constructAssociatedTypeNode(SDKContext &Ctx,
+                                            AssociatedTypeDecl *ATD) {
+  auto Asso = SDKNodeInitInfo(Ctx, ATD).
+    createSDKNode(SDKNodeKind::DeclAssociatedType);
+  if (auto DT = ATD->getDefaultDefinitionType()) {
+    Asso->addChild(constructTypeNode(Ctx, DT));
+  }
+  return Asso;
+}
+
 static void addMembersToRoot(SDKContext &Ctx, SDKNode *Root,
                              IterableDeclContext *Context,
                              std::set<ExtensionDecl*> &HandledExts) {
@@ -1268,6 +1283,8 @@ static void addMembersToRoot(SDKContext &Ctx, SDKNode *Root,
       Root->addChild(constructVarNode(Ctx, EED));
     } else if (auto NTD = dyn_cast<NominalTypeDecl>(Member)) {
       Root->addChild(constructTypeDeclNode(Ctx, NTD, HandledExts));
+    } else if (auto ATD = dyn_cast<AssociatedTypeDecl>(Member)) {
+      Root->addChild(constructAssociatedTypeNode(Ctx, ATD));
     }
   }
 }
diff --git a/tools/swift-api-digester/ModuleAnalyzerNodes.h b/tools/swift-api-digester/ModuleAnalyzerNodes.h
index 88358634cca..71e37ac6c8d 100644
--- a/tools/swift-api-digester/ModuleAnalyzerNodes.h
+++ b/tools/swift-api-digester/ModuleAnalyzerNodes.h
@@ -440,6 +440,15 @@ public:
   static bool classof(const SDKNode *N);
 };
 
+class SDKNodeDeclAssociatedType: public SDKNodeDecl {
+public:
+  SDKNodeDeclAssociatedType(SDKNodeInitInfo Info);
+  const SDKNodeType* getDefault() const {
+    return getChildrenCount() ? getOnlyChild()->getAs<SDKNodeType>(): nullptr;
+  }
+  static bool classof(const SDKNode *N);
+};
+
 class SDKNodeDeclVar : public SDKNodeDecl {
   Optional<unsigned> FixedBinaryOrder;
 public:
diff --git a/tools/swift-api-digester/swift-api-digester.cpp b/tools/swift-api-digester/swift-api-digester.cpp
index 5cb4c3a6edb..a532c9d8168 100644
--- a/tools/swift-api-digester/swift-api-digester.cpp
+++ b/tools/swift-api-digester/swift-api-digester.cpp
@@ -860,6 +860,7 @@ public:
       break;
     }
 
+    case SDKNodeKind::DeclAssociatedType:
     case SDKNodeKind::DeclFunction:
     case SDKNodeKind::DeclSetter:
     case SDKNodeKind::DeclGetter: