diff --git a/clang/test/PCH/cxx17-deduction-guide-decl.cpp b/clang/test/PCH/cxx17-deduction-guide-decl.cpp
new file mode 100644
--- /dev/null
+++ b/clang/test/PCH/cxx17-deduction-guide-decl.cpp
@@ -0,0 +1,24 @@
+// Test with pch.
+// RUN: %clang_cc1 -emit-pch -std=c++17  -o %t %s
+// RUN: %clang_cc1 -include-pch %t -emit-llvm -std=c++17 -o - %s
+
+#ifndef HEADER
+#define HEADER
+
+namespace RP47219 {
+typedef int MyInt;
+template <typename T>
+class Some {
+ public:
+  explicit Some(T, MyInt) {}
+};
+
+struct Foo {};
+void ParseNatural() {
+  Some(Foo(), 1);
+}
+}
+
+#else
+
+#endif