1 files changed, 3 insertions, 0 deletions
diff --git a/lib/Sema/Sema.cpp b/lib/Sema/Sema.cpp
index 6f0db6ce1c..a18f71422f 100644
--- a/lib/Sema/Sema.cpp
+++ b/lib/Sema/Sema.cpp
@@ -542,6 +542,9 @@ void Sema::getUndefinedButUsed(
     // __attribute__((weakref)) is basically a definition.
     if (ND->hasAttr<WeakRefAttr>()) continue;
 
+    if (isa<CXXDeductionGuideDecl>(ND))
+      continue;
+
     if (FunctionDecl *FD = dyn_cast<FunctionDecl>(ND)) {
       if (FD->isDefined())
         continue;