diff --git a/alib2algo_experimental/src/graph/datastructs/BinomialHeap.h b/alib2algo_experimental/src/graph/datastructs/BinomialHeap.h
index e6a77ffa3392a39953e994190e0cbecc761e4f08..0185cdc10b3adeef162acc1b76abb704174f9674 100644
--- a/alib2algo_experimental/src/graph/datastructs/BinomialHeap.h
+++ b/alib2algo_experimental/src/graph/datastructs/BinomialHeap.h
@@ -8,6 +8,8 @@
 #ifndef BINOMIAL_HEAP_INCLUDED
 #define BINOMIAL_HEAP_INCLUDED
 
+#include <sys/types.h>
+
 #include <stdexcept>
 
 /// binomial heap used as mergeable priority queue
diff --git a/alib2algo_experimental/src/graph/datastructs/Components.h b/alib2algo_experimental/src/graph/datastructs/Components.h
index d1e4cbc5ba751e18dff4073066f1f73822a6a271..74737e278f14975e5405d9107c1e14930db60350 100644
--- a/alib2algo_experimental/src/graph/datastructs/Components.h
+++ b/alib2algo_experimental/src/graph/datastructs/Components.h
@@ -5,6 +5,8 @@
  *       Author: Jan Broz
  */
 
+#include <sys/types.h>
+
 #include <unordered_map>
 
 #include <graph/common/Node.h>