diff --git a/.gitignore b/.gitignore
index 3a9c2be..5cec9c7 100644
--- a/.gitignore
+++ b/.gitignore
@@ -68,4 +68,8 @@ target/
 .ipynb_checkpoints
 
 # emacs
-*~
\ No newline at end of file
+*~
+
+# Pipenv
+Pipfile
+Pipfile.lock
diff --git a/extinction.pyx b/extinction.pyx
index 5103fce..5323ca3 100644
--- a/extinction.pyx
+++ b/extinction.pyx
@@ -154,10 +154,10 @@ def ccm89(double[:] wave, double a_v, double r_v, unit='aa',
         double b = 0.0
 
     if out is None:
-        out = np.empty(n, dtype=np.float)
+        out = np.empty(n, dtype=np.float64)
     else:
         assert out.shape == wave.shape
-        assert out.dtype == np.float
+        assert out.dtype == np.float64
 
     cdef scalar_func convert_wave
     if unit == 'aa':
@@ -262,10 +262,10 @@ def odonnell94(double[:] wave, double a_v, double r_v, unit='aa',
         double b = 0.0
 
     if out is None:
-        out = np.empty(n, dtype=np.float)
+        out = np.empty(n, dtype=np.float64)
     else:
         assert out.shape == wave.shape
-        assert out.dtype == np.float
+        assert out.dtype == np.float64
 
     cdef scalar_func convert_wave
     if unit == 'aa':
@@ -697,10 +697,10 @@ def calzetti00(double[:] wave, double a_v, double r_v, unit='aa',
         double b = 0.0
 
     if out is None:
-        out = np.empty(n, dtype=np.float)
+        out = np.empty(n, dtype=np.float64)
     else:
         assert out.shape == wave.shape
-        assert out.dtype == np.float
+        assert out.dtype == np.float64
 
     cdef scalar_func convert_wave
     if unit == 'aa':