diff --git a/include/Support/hash_map b/include/Support/hash_map
index ce4c42f6ab9..72d8bf36ba5 100644
--- a/include/Support/hash_map
+++ b/include/Support/hash_map
@@ -42,6 +42,10 @@ using HASH_NAMESPACE::hash_map;
 using HASH_NAMESPACE::hash_multimap;
 using HASH_NAMESPACE::hash;
 
+/* Include vector because ext/hash_map includes stl_vector.h and leaves
+   out specializations like stl_bvector.h, causing link conflicts. */
+#include <vector>
+
 #include <Support/HashExtras.h>
 
 #endif
diff --git a/include/Support/hash_set b/include/Support/hash_set
index 045083c8cd5..46e75d8b94f 100644
--- a/include/Support/hash_set
+++ b/include/Support/hash_set
@@ -41,6 +41,10 @@
 using HASH_NAMESPACE::hash_set;
 using HASH_NAMESPACE::hash;
 
+/* Include vector because ext/hash_set includes stl_vector.h and leaves
+   out specializations like stl_bvector.h, causing link conflicts. */
+#include <vector>
+
 #include <Support/HashExtras.h>
 
 #endif