diff --git a/lib/Sema/SemaTemplateDeduction.cpp b/lib/Sema/SemaTemplateDeduction.cpp
index c80e2e0..79cbc5a 100644
--- a/lib/Sema/SemaTemplateDeduction.cpp
+++ b/lib/Sema/SemaTemplateDeduction.cpp
@@ -704,9 +704,10 @@
       }
       if (const DependentSizedArrayType *DependentArrayArg
             = dyn_cast<DependentSizedArrayType>(ArrayArg))
-        return DeduceNonTypeTemplateArgument(S, NTTP,
-                                             DependentArrayArg->getSizeExpr(),
-                                             Info, Deduced);
+        if (DependentArrayArg->getSizeExpr())
+          return DeduceNonTypeTemplateArgument(S, NTTP,
+                                               DependentArrayArg->getSizeExpr(),
+                                               Info, Deduced);
 
       // Incomplete type does not match a dependently-sized array type
       return Sema::TDK_NonDeducedMismatch;