diff --git a/clang/lib/AST/ASTImporter.cpp b/clang/lib/AST/ASTImporter.cpp
--- a/clang/lib/AST/ASTImporter.cpp
+++ b/clang/lib/AST/ASTImporter.cpp
@@ -3842,6 +3842,15 @@
   else
     return Imp.takeError();
 
+  Expr *DefaultArg = nullptr;
+  if (D->hasUninstantiatedDefaultArg()) {
+    if (Error Err = importInto(DefaultArg, D->getUninstantiatedDefaultArg()))
+      return std::move(Err);
+  } else if (D->hasDefaultArg()) {
+    if (Error Err = importInto(DefaultArg, D->getDefaultArg()))
+      return std::move(Err);
+  }
+
   ParmVarDecl *ToParm;
   if (GetImportedOrCreateDecl(ToParm, D, Importer.getToContext(), DC,
                               ToInnerLocStart, ToLocation,
@@ -3853,19 +3862,12 @@
   // Set the default argument.
   ToParm->setHasInheritedDefaultArg(D->hasInheritedDefaultArg());
   ToParm->setKNRPromoted(D->isKNRPromoted());
-
   if (D->hasUninstantiatedDefaultArg()) {
-    if (auto ToDefArgOrErr = import(D->getUninstantiatedDefaultArg()))
-      ToParm->setUninstantiatedDefaultArg(*ToDefArgOrErr);
-    else
-      return ToDefArgOrErr.takeError();
+    ToParm->setUninstantiatedDefaultArg(DefaultArg);
   } else if (D->hasUnparsedDefaultArg()) {
     ToParm->setUnparsedDefaultArg();
   } else if (D->hasDefaultArg()) {
-    if (auto ToDefArgOrErr = import(D->getDefaultArg()))
-      ToParm->setDefaultArg(*ToDefArgOrErr);
-    else
-      return ToDefArgOrErr.takeError();
+    ToParm->setDefaultArg(DefaultArg);
   }
 
   if (D->isObjCMethodParameter()) {
diff --git a/clang/test/Analysis/Inputs/ctu-other.cpp b/clang/test/Analysis/Inputs/ctu-other.cpp
--- a/clang/test/Analysis/Inputs/ctu-other.cpp
+++ b/clang/test/Analysis/Inputs/ctu-other.cpp
@@ -131,3 +131,22 @@
   const unsigned int b;
 };
 U extU = {.a = 4};
+
+struct DefParmContext {
+  static const int I;
+  int f();
+};
+
+int fDefParm(int I = DefParmContext::I) {
+  return I;
+}
+
+int testDefParmIncompleteImport(int I) {
+  return fDefParm(I);
+}
+
+const int DefParmContext::I = 0;
+
+int DefParmContext::f() {
+  return fDefParm();
+}
diff --git a/clang/test/Analysis/Inputs/ctu-other.cpp.externalDefMap.txt b/clang/test/Analysis/Inputs/ctu-other.cpp.externalDefMap.txt
--- a/clang/test/Analysis/Inputs/ctu-other.cpp.externalDefMap.txt
+++ b/clang/test/Analysis/Inputs/ctu-other.cpp.externalDefMap.txt
@@ -25,3 +25,4 @@
 c:@extSubSCN ctu-other.cpp.ast
 c:@extSCC ctu-other.cpp.ast
 c:@extU ctu-other.cpp.ast
+c:@F@testDefParmIncompleteImport#I# ctu-other.cpp.ast
diff --git a/clang/test/Analysis/ctu-main.cpp b/clang/test/Analysis/ctu-main.cpp
--- a/clang/test/Analysis/ctu-main.cpp
+++ b/clang/test/Analysis/ctu-main.cpp
@@ -112,6 +112,8 @@
   clang_analyzer_eval(obj->fvcl(1) == 8);      // expected-warning{{FALSE}} expected-warning{{TRUE}}
 }
 
+extern int testDefParmIncompleteImport(int);
+
 int main() {
   clang_analyzer_eval(f(3) == 2); // expected-warning{{TRUE}}
   clang_analyzer_eval(f(4) == 3); // expected-warning{{TRUE}}
@@ -144,4 +146,6 @@
   clang_analyzer_eval(extSubSCN.a == 1); // expected-warning{{TRUE}}
   // clang_analyzer_eval(extSCC.a == 7); // TODO
   clang_analyzer_eval(extU.a == 4); // expected-warning{{TRUE}}
+
+  clang_analyzer_eval(testDefParmIncompleteImport(9) == 9); // expected-warning{{TRUE}}
 }