diff --git a/rocketpy/mathutils/function.py b/rocketpy/mathutils/function.py
index 2dab353de..8bdad9d2b 100644
--- a/rocketpy/mathutils/function.py
+++ b/rocketpy/mathutils/function.py
@@ -1840,7 +1840,9 @@ def __add__(self, other):
                 return Function(lambda x: (self.get_value(x) + other(x)))
         # If other is Float except...
         except AttributeError:
-            if isinstance(other, (float, int, complex, np.ndarray)):
+            if isinstance(
+                other, (float, int, complex, np.ndarray, np.integer, np.floating)
+            ):
                 # Check if Function object source is array or callable
                 if isinstance(self.source, np.ndarray):
                     # Operate on grid values
@@ -1970,7 +1972,9 @@ def __mul__(self, other):
                 return Function(lambda x: (self.get_value(x) * other(x)))
         # If other is Float except...
         except AttributeError:
-            if isinstance(other, (float, int, complex, np.ndarray)):
+            if isinstance(
+                other, (float, int, complex, np.ndarray, np.integer, np.floating)
+            ):
                 # Check if Function object source is array or callable
                 if isinstance(self.source, np.ndarray):
                     # Operate on grid values
@@ -2059,7 +2063,9 @@ def __truediv__(self, other):
                 return Function(lambda x: (self.get_value_opt(x) / other(x)))
         # If other is Float except...
         except AttributeError:
-            if isinstance(other, (float, int, complex, np.ndarray)):
+            if isinstance(
+                other, (float, int, complex, np.ndarray, np.integer, np.floating)
+            ):
                 # Check if Function object source is array or callable
                 if isinstance(self.source, np.ndarray):
                     # Operate on grid values
@@ -2098,7 +2104,9 @@ def __rtruediv__(self, other):
             A Function object which gives the result of other(x)/self(x).
         """
         # Check if Function object source is array and other is float
-        if isinstance(other, (float, int, complex, np.ndarray)):
+        if isinstance(
+            other, (float, int, complex, np.ndarray, np.integer, np.floating)
+        ):
             if isinstance(self.source, np.ndarray):
                 # Operate on grid values
                 ys = other / self.y_array
@@ -2166,7 +2174,9 @@ def __pow__(self, other):
                 return Function(lambda x: (self.get_value_opt(x) ** other(x)))
         # If other is Float except...
         except AttributeError:
-            if isinstance(other, (float, int, complex, np.ndarray)):
+            if isinstance(
+                other, (float, int, complex, np.ndarray, np.integer, np.floating)
+            ):
                 # Check if Function object source is array or callable
                 if isinstance(self.source, np.ndarray):
                     # Operate on grid values
@@ -2205,7 +2215,9 @@ def __rpow__(self, other):
             A Function object which gives the result of other(x)**self(x).
         """
         # Check if Function object source is array and other is float
-        if isinstance(other, (float, int, complex, np.ndarray)):
+        if isinstance(
+            other, (float, int, complex, np.ndarray, np.integer, np.floating)
+        ):
             if isinstance(self.source, np.ndarray):
                 # Operate on grid values
                 ys = other**self.y_array