diff --git a/distancematrix.h b/distancematrix.h
index 3d5075e..1620436 100644
--- a/distancematrix.h
+++ b/distancematrix.h
@@ -28,6 +28,7 @@
 #include <sstream>     //for std::stringstream
 #include <vector>      //for std::vector
 #include <math.h>      //for floor()
+#include <cstdint>  //for gcc13
 #if USE_GZSTREAM
 #include <utils/gzstream.h>  //for igzstream and pigzstream
 #else
diff --git a/flatmatrix.h b/flatmatrix.h
index e647950..13a3b37 100644
--- a/flatmatrix.h
+++ b/flatmatrix.h
@@ -26,6 +26,7 @@
 #include <stdlib.h> //for size_t
 #include <vector>   //for std::vector
 #include <string>   //for std::string
+#include <cstdint>  //for gcc13
 #include <utils/vectortypes.h> //for StrVector
 
 class FlatMatrix {
diff --git a/utils/vectortypes.h b/utils/vectortypes.h
index 310435f..4a18a49 100644
--- a/utils/vectortypes.h
+++ b/utils/vectortypes.h
@@ -10,6 +10,7 @@
 #include <vector>
 #include <algorithm> //for std::transform
 #include <string>    //for std::string
+#include <cstdint>  //for gcc13
 
 /**
         vector of double number