diff --git a/clang/include/clang/AST/ASTConcept.h b/clang/include/clang/AST/ASTConcept.h
index 832918785434d..d40d3636287e7 100644
--- a/clang/include/clang/AST/ASTConcept.h
+++ b/clang/include/clang/AST/ASTConcept.h
@@ -14,16 +14,21 @@
 #ifndef LLVM_CLANG_AST_ASTCONCEPT_H
 #define LLVM_CLANG_AST_ASTCONCEPT_H
 
-#include "clang/AST/Decl.h"
-#include "clang/AST/Expr.h"
-#include "clang/AST/PrettyPrinter.h"
+#include "clang/AST/DeclarationName.h"
+#include "clang/AST/NestedNameSpecifier.h"
+#include "clang/AST/TemplateBase.h"
 #include "clang/Basic/SourceLocation.h"
+#include "llvm/ADT/FoldingSet.h"
 #include "llvm/ADT/PointerUnion.h"
 #include "llvm/ADT/SmallVector.h"
 #include <utility>
 
 namespace clang {
+
 class ConceptDecl;
+class Expr;
+class NamedDecl;
+struct PrintingPolicy;
 
 /// The result of a constraint satisfaction check, containing the necessary
 /// information to diagnose an unsatisfied constraint.
@@ -157,10 +162,7 @@ class ConceptReference {
   Create(const ASTContext &C, NestedNameSpecifierLoc NNS,
          SourceLocation TemplateKWLoc, DeclarationNameInfo ConceptNameInfo,
          NamedDecl *FoundDecl, ConceptDecl *NamedConcept,
-         const ASTTemplateArgumentListInfo *ArgsAsWritten) {
-    return new (C) ConceptReference(NNS, TemplateKWLoc, ConceptNameInfo,
-                                    FoundDecl, NamedConcept, ArgsAsWritten);
-  }
+         const ASTTemplateArgumentListInfo *ArgsAsWritten);
 
   const NestedNameSpecifierLoc &getNestedNameSpecifierLoc() const {
     return NestedNameSpec;
diff --git a/clang/include/clang/AST/ASTContext.h b/clang/include/clang/AST/ASTContext.h
index 181b3362f7d64..8dc8bc262bbe3 100644
--- a/clang/include/clang/AST/ASTContext.h
+++ b/clang/include/clang/AST/ASTContext.h
@@ -21,7 +21,6 @@
 #include "clang/AST/Decl.h"
 #include "clang/AST/DeclarationName.h"
 #include "clang/AST/ExternalASTSource.h"
-#include "clang/AST/NestedNameSpecifier.h"
 #include "clang/AST/PrettyPrinter.h"
 #include "clang/AST/RawCommentList.h"
 #include "clang/AST/TemplateName.h"
@@ -81,6 +80,7 @@ class MangleNumberingContext;
 class MemberSpecializationInfo;
 class Module;
 struct MSGuidDeclParts;
+class NestedNameSpecifier;
 class ObjCCategoryDecl;
 class ObjCCategoryImplDecl;
 class ObjCContainerDecl;
diff --git a/clang/lib/AST/ASTConcept.cpp b/clang/lib/AST/ASTConcept.cpp
index 8f2d945721843..b3ec99448b3e1 100644
--- a/clang/lib/AST/ASTConcept.cpp
+++ b/clang/lib/AST/ASTConcept.cpp
@@ -13,10 +13,9 @@
 
 #include "clang/AST/ASTConcept.h"
 #include "clang/AST/ASTContext.h"
-#include "clang/AST/Decl.h"
-#include "clang/AST/TemplateBase.h"
+#include "clang/AST/PrettyPrinter.h"
 #include "llvm/ADT/ArrayRef.h"
-#include "llvm/ADT/FoldingSet.h"
+
 using namespace clang;
 
 namespace {
@@ -89,3 +88,27 @@ void ConstraintSatisfaction::Profile(
   for (auto &Arg : TemplateArgs)
     Arg.Profile(ID, C);
 }
+
+ConceptReference *
+ConceptReference::Create(const ASTContext &C, NestedNameSpecifierLoc NNS,
+                         SourceLocation TemplateKWLoc,
+                         DeclarationNameInfo ConceptNameInfo,
+                         NamedDecl *FoundDecl, ConceptDecl *NamedConcept,
+                         const ASTTemplateArgumentListInfo *ArgsAsWritten) {
+  return new (C) ConceptReference(NNS, TemplateKWLoc, ConceptNameInfo,
+                                  FoundDecl, NamedConcept, ArgsAsWritten);
+}
+
+void ConceptReference::print(llvm::raw_ostream &OS,
+                             const PrintingPolicy &Policy) const {
+  if (NestedNameSpec)
+    NestedNameSpec.getNestedNameSpecifier()->print(OS, Policy);
+  ConceptName.printName(OS, Policy);
+  if (hasExplicitTemplateArgs()) {
+    OS << "<";
+    // FIXME: Find corresponding parameter for argument
+    for (auto &ArgLoc : ArgsAsWritten->arguments())
+      ArgLoc.getArgument().print(Policy, OS, /*IncludeType*/ false);
+    OS << ">";
+  }
+}
diff --git a/clang/lib/AST/DeclTemplate.cpp b/clang/lib/AST/DeclTemplate.cpp
index 6490999ce7ea2..5e2742b4949f2 100644
--- a/clang/lib/AST/DeclTemplate.cpp
+++ b/clang/lib/AST/DeclTemplate.cpp
@@ -1552,20 +1552,6 @@ BuiltinTemplateDecl::BuiltinTemplateDecl(const ASTContext &C, DeclContext *DC,
                    createBuiltinTemplateParameterList(C, DC, BTK)),
       BTK(BTK) {}
 
-void ConceptReference::print(llvm::raw_ostream &OS,
-                             const PrintingPolicy &Policy) const {
-  if (NestedNameSpec)
-    NestedNameSpec.getNestedNameSpecifier()->print(OS, Policy);
-  ConceptName.printName(OS, Policy);
-  if (hasExplicitTemplateArgs()) {
-    OS << "<";
-    // FIXME: Find corresponding parameter for argument
-    for (auto &ArgLoc : ArgsAsWritten->arguments())
-      ArgLoc.getArgument().print(Policy, OS, /*IncludeType*/ false);
-    OS << ">";
-  }
-}
-
 TemplateParamObjectDecl *TemplateParamObjectDecl::Create(const ASTContext &C,
                                                          QualType T,
                                                          const APValue &V) {