diff --git a/clang/lib/Sema/SemaChecking.cpp b/clang/lib/Sema/SemaChecking.cpp
--- a/clang/lib/Sema/SemaChecking.cpp
+++ b/clang/lib/Sema/SemaChecking.cpp
@@ -5776,6 +5776,8 @@
           checkAIXMemberAlignment((Arg->getExprLoc()), Arg);
 
         QualType ParamTy = Proto->getParamType(ArgIdx);
+        if (ParamTy->containsErrors())
+          continue;
         QualType ArgTy = Arg->getType();
         CheckArgAlignment(Arg->getExprLoc(), FDecl, std::to_string(ArgIdx + 1),
                           ArgTy, ParamTy);
diff --git a/clang/test/SemaCXX/recovery-expr-type.cpp b/clang/test/SemaCXX/recovery-expr-type.cpp
--- a/clang/test/SemaCXX/recovery-expr-type.cpp
+++ b/clang/test/SemaCXX/recovery-expr-type.cpp
@@ -162,3 +162,15 @@
   b = __builtin_object_size(c, 0); // crash2
 }
 }
+
+namespace test15 {
+const UnknownType SZ = 8; // expected-error {{unknown type}}
+typedef unsigned char UC;
+void f() {
+  struct {
+    void m(UC (&)[SZ]) {}
+  } S;
+  unsigned char A[8];
+  S.m(A); // no crash
+}
+}