diff --git a/clang/lib/Sema/SemaOverload.cpp b/clang/lib/Sema/SemaOverload.cpp
index 29ba34479dab..782c377e3202 100644
--- a/clang/lib/Sema/SemaOverload.cpp
+++ b/clang/lib/Sema/SemaOverload.cpp
@@ -11426,6 +11426,10 @@ static void AddOverloadedCallCandidate(Sema &S,
       assert(!KnownValid && "Explicit template arguments?");
       return;
     }
+    // Prevent ill-formed function decls to be added as overload candidates.
+    if (!dyn_cast<FunctionProtoType>(Func->getType()->getAs<FunctionType>()))
+      return;
+
     S.AddOverloadCandidate(Func, FoundDecl, Args, CandidateSet,
                            /*SuppressUsedConversions=*/false,
                            PartialOverloading);
diff --git a/clang/test/Modules/Inputs/malformed-overload/X.h b/clang/test/Modules/Inputs/malformed-overload/X.h
new file mode 100644
index 000000000000..b659406e16ed
--- /dev/null
+++ b/clang/test/Modules/Inputs/malformed-overload/X.h
@@ -0,0 +1,2 @@
+@class NSString;
+extern void NSLog(NSString *format, ...) __attribute__((format(__NSString__, 1, 2))) __attribute__((not_tail_called));
diff --git a/clang/test/Modules/Inputs/malformed-overload/module.modulemap b/clang/test/Modules/Inputs/malformed-overload/module.modulemap
new file mode 100644
index 000000000000..8fe4c92a1738
--- /dev/null
+++ b/clang/test/Modules/Inputs/malformed-overload/module.modulemap
@@ -0,0 +1,4 @@
+module X {
+  header "X.h"
+  export *
+}
diff --git a/clang/test/Modules/malformed-overload.m b/clang/test/Modules/malformed-overload.m
new file mode 100644
index 000000000000..ad6db8a46c31
--- /dev/null
+++ b/clang/test/Modules/malformed-overload.m
@@ -0,0 +1,8 @@
+// RUN: %clang_cc1 -fsyntax-only -I%S/Inputs/malformed-overload -fmodules -fimplicit-module-maps -fmodules-cache-path=tmp -verify %s
+NSLog(@"%@", path); // expected-error {{expected parameter declarator}} expected-error {{expected ')'}} expected-warning {{type specifier missing}} expected-warning {{incompatible redeclaration}} expected-note {{to match this '('}} expected-note {{'NSLog' is a builtin with type}}
+#import "X.h"
+
+@class NSString;
+void f(NSString *a) {
+ NSLog(@"***** failed to get URL for %@", a);
+}