diff --git a/lib/Sema/TypeCheckNameLookup.cpp b/lib/Sema/TypeCheckNameLookup.cpp
index 7ba8ba3d4ac7f..5eb91532f8815 100644
--- a/lib/Sema/TypeCheckNameLookup.cpp
+++ b/lib/Sema/TypeCheckNameLookup.cpp
@@ -252,27 +252,36 @@ convertToUnqualifiedLookupOptions(NameLookupOptions options) {
   return newOptions;
 }
 
+/// HACK: Qualified lookup cannot be allowed to synthesize CodingKeys because
+/// it would lead to a number of egregious cycles through QualifiedLookupRequest
+/// when we resolve the protocol conformance. Codable's magic has pushed its way
+/// so deeply into the compiler, when doing unqualified lookup we have to
+/// pessimistically force every nominal context above this one to synthesize it
+/// in the event the user needs it from e.g. a non-primary input.
+///
+/// We can undo this if Codable's semantic content is divorced from its
+/// syntactic content - so we synthesize just enough to allow lookups to
+/// succeed, but don't force protocol conformances while we're doing it.
+static void synthesizeCodingKeysIfNeededForUnqualifiedLookup(ASTContext &ctx,
+                                                             DeclContext *dc,
+                                                             DeclNameRef name) {
+  if (name.getBaseIdentifier() != ctx.Id_CodingKeys)
+    return;
+
+  for (auto typeCtx = dc->getInnermostTypeContext(); typeCtx != nullptr;
+       typeCtx = typeCtx->getParent()->getInnermostTypeContext()) {
+    if (auto *nominal = typeCtx->getSelfNominalTypeDecl())
+      nominal->synthesizeSemanticMembersIfNeeded(name.getFullName());
+  }
+}
+
 LookupResult TypeChecker::lookupUnqualified(DeclContext *dc, DeclNameRef name,
                                             SourceLoc loc,
                                             NameLookupOptions options) {
   auto &ctx = dc->getASTContext();
-  // HACK: Qualified lookup cannot be allowed to synthesize CodingKeys because
-  // it would lead to a number of egregious cycles through
-  // QualifiedLookupRequest when we resolve the protocol conformance. Codable's
-  // magic has pushed its way so deeply into the compiler, we have to
-  // pessimistically force every nominal context above this one to synthesize
-  // it in the event the user needs it from e.g. a non-primary input.
-  // We can undo this if Codable's semantic content is divorced from its
-  // syntactic content - so we synthesize just enough to allow lookups to
-  // succeed, but don't force protocol conformances while we're doing it.
-  if (name.getBaseIdentifier() == ctx.Id_CodingKeys) {
-    for (auto typeCtx = dc->getInnermostTypeContext(); typeCtx != nullptr;
-         typeCtx = typeCtx->getParent()->getInnermostTypeContext()) {
-      if (auto *nominal = typeCtx->getSelfNominalTypeDecl()) {
-        nominal->synthesizeSemanticMembersIfNeeded(name.getFullName());
-      }
-    }
-  }
+
+  // HACK: Synthesize CodingKeys if needed.
+  synthesizeCodingKeysIfNeededForUnqualifiedLookup(ctx, dc, name);
 
   auto ulOptions = convertToUnqualifiedLookupOptions(options);
   auto descriptor = UnqualifiedLookupDescriptor(name, dc, loc, ulOptions);
@@ -314,6 +323,10 @@ TypeChecker::lookupUnqualifiedType(DeclContext *dc, DeclNameRef name,
                                    SourceLoc loc,
                                    NameLookupOptions options) {
   auto &ctx = dc->getASTContext();
+
+  // HACK: Synthesize CodingKeys if needed.
+  synthesizeCodingKeysIfNeededForUnqualifiedLookup(ctx, dc, name);
+
   auto ulOptions = convertToUnqualifiedLookupOptions(options) |
                    UnqualifiedLookupFlags::TypeLookup;
   {
diff --git a/test/IDE/complete_rdar146055457.swift b/test/IDE/complete_rdar146055457.swift
new file mode 100644
index 0000000000000..c86a485e4da76
--- /dev/null
+++ b/test/IDE/complete_rdar146055457.swift
@@ -0,0 +1,14 @@
+// RUN: %batch-code-completion
+
+// rdar://146055457 - Make sure we synthesize CodingKeys
+
+struct S: Encodable {
+  var a: String
+  var b: String
+
+  private var foo: CodingKeys {
+    .#^COMPLETE^#
+    // COMPLETE-DAG: Decl[EnumElement]/CurrNominal/Flair[ExprSpecific]/TypeRelation[Convertible]: a[#CodingKeys#]; name=a
+    // COMPLETE-DAG: Decl[EnumElement]/CurrNominal/Flair[ExprSpecific]/TypeRelation[Convertible]: b[#CodingKeys#]; name=b
+  }
+}