diff --git a/olm/general.py b/olm/general.py
index 3410817..d424004 100644
--- a/olm/general.py
+++ b/olm/general.py
@@ -399,17 +399,17 @@ def __init__(self, constituents, concentrations, units, T=25., T_units='C', cond
                 else:
                     print("Units for " + ion + " are incorrect, must either be mg/L, mmol/L, or mol/L")
             if T_units == 'C':
-                self.T_C = np.float(T)
+                self.T_C = np.float64(T)
                 self.T_K = CtoK(self.T_C)
             elif T_units == 'K':
-                self.T_K = np.float(T)
+                self.T_K = np.float64(T)
                 self.T_C = KtoC(self.T_K)
             else:
                 print("T_units must equal either C or K.")
             if cond != None:
-                self.cond = np.float(cond)
+                self.cond = np.float64(cond)
             if pH != None:
-                self.pH = np.float(pH)
+                self.pH = np.float64(pH)
             #loop through ions and calculate activities
             for key, ion_dict in self.ions.items():
                 if ('conc_mol' in ion_dict):
diff --git a/setup.py b/setup.py
index a51fde9..e76484d 100644
--- a/setup.py
+++ b/setup.py
@@ -3,11 +3,11 @@
 
 
 setup(name='olm-karst',
-    version='0.39',
+    version='0.40',
     author='Matthew D. Covington',
       author_email = 'mcoving@uark.edu',
     url='https://github.com/speleophysics/olm/',
-      download_url = 'https://github.com/CovingtonResearchGroup/olm/archive/refs/tags/0.39a.tar.gz',
+      download_url = 'https://github.com/CovingtonResearchGroup/olm/archive/refs/tags/0.40.tar.gz',
     packages=['olm', 'olm.USGS', 'olm.loggers'],
       install_requires = ['numpy',
                           'scipy',