diff --git a/pymarchenko/marchenko.py b/pymarchenko/marchenko.py
index 0a4472e..f852ee6 100755
--- a/pymarchenko/marchenko.py
+++ b/pymarchenko/marchenko.py
@@ -291,7 +291,7 @@ def apply_onepoint(self, trav, G0=None, nfft=None, rtm=False, greens=False,
         """
         # Create window
         trav_off = trav - self.toff
-        trav_off = np.round(trav_off / self.dt).astype(np.int)
+        trav_off = np.round(trav_off / self.dt).astype(np.int32)
 
         w = np.zeros((self.nr, self.nt), dtype=self.dtype)
         for ir in range(self.nr):
@@ -459,7 +459,7 @@ def apply_multiplepoints(self, trav, G0=None, nfft=None,
 
         # Create window
         trav_off = trav - self.toff
-        trav_off = np.round(trav_off / self.dt).astype(np.int)
+        trav_off = np.round(trav_off / self.dt).astype(np.int32)
 
         w = np.zeros((self.nr, nvs, self.nt), dtype=self.dtype)
         for ir in range(self.nr):
diff --git a/pymarchenko/neumarchenko.py b/pymarchenko/neumarchenko.py
index 2e1f6be..32f4eb1 100755
--- a/pymarchenko/neumarchenko.py
+++ b/pymarchenko/neumarchenko.py
@@ -220,7 +220,7 @@ def apply_onepoint(self, trav, G0=None, nfft=None, rtm=False, greens=False,
         """
         # Create window
         trav_off = trav - self.toff
-        trav_off = np.round(trav_off / self.dt).astype(np.int)
+        trav_off = np.round(trav_off / self.dt).astype(np.int32)
 
         w = np.zeros((self.nr, self.nt), dtype=self.dtype)
         for ir in range(self.nr):
diff --git a/pymarchenko/raymarchenko.py b/pymarchenko/raymarchenko.py
index 1c2bfa3..bfbc542 100644
--- a/pymarchenko/raymarchenko.py
+++ b/pymarchenko/raymarchenko.py
@@ -242,9 +242,9 @@ def apply_onepoint(self, travsrc, travrec, G0=None, nfft=None, rtm=False, greens
         """
         # Create windows
         travsrc_off = travsrc - self.toff
-        travsrc_off = np.round(travsrc_off / self.dt).astype(np.int)
+        travsrc_off = np.round(travsrc_off / self.dt).astype(np.int32)
         travrec_off = travrec - self.toff
-        travrec_off = np.round(travrec_off / self.dt).astype(np.int)
+        travrec_off = np.round(travrec_off / self.dt).astype(np.int32)
 
         ws = np.zeros((self.ns, self.nt), dtype=self.dtype)
         wr = np.zeros((self.nr, self.nt), dtype=self.dtype)
@@ -426,9 +426,9 @@ def apply_multiplepoints(self, travsrc, travrec, G0=None, nfft=None,
 
         # Create window
         travsrc_off = travsrc - self.toff
-        travsrc_off = np.round(travsrc_off / self.dt).astype(np.int)
+        travsrc_off = np.round(travsrc_off / self.dt).astype(np.int32)
         travrec_off = travrec - self.toff
-        travrec_off = np.round(travrec_off / self.dt).astype(np.int)
+        travrec_off = np.round(travrec_off / self.dt).astype(np.int32)
 
         ws = np.zeros((self.ns, nvs, self.nt), dtype=self.dtype)
         wr = np.zeros((self.nr, nvs, self.nt), dtype=self.dtype)