1 files changed, 2 insertions, 1 deletions
diff --git a/libcxx/test/std/containers/sequences/deque/deque.modifiers/emplace.pass.cpp b/libcxx/test/std/containers/sequences/deque/deque.modifiers/emplace.pass.cpp
index 713f2159e59..33a0b6df364 100644
--- a/libcxx/test/std/containers/sequences/deque/deque.modifiers/emplace.pass.cpp
+++ b/libcxx/test/std/containers/sequences/deque/deque.modifiers/emplace.pass.cpp
@@ -15,6 +15,7 @@
 
 #include <deque>
 #include <cassert>
+#include <cstddef>
 
 #include "../../../Emplaceable.h"
 #include "min_allocator.h"
@@ -51,7 +52,7 @@ test(int P, C& c1)
     CI i = c1.emplace(c1.begin() + P, Emplaceable(1, 2.5));
     assert(i == c1.begin() + P);
     assert(c1.size() == c1_osize + 1);
-    assert(distance(c1.begin(), c1.end()) == c1.size());
+    assert(static_cast<std::size_t>(distance(c1.begin(), c1.end())) == c1.size());
     assert(*i == Emplaceable(1, 2.5));
 }