diff --git a/pyerrors/correlators.py b/pyerrors/correlators.py
index 6459d466..ea767ec5 100644
--- a/pyerrors/correlators.py
+++ b/pyerrors/correlators.py
@@ -1033,6 +1033,8 @@ class Corr:
     # This is because Obs*Corr checks Obs.__mul__ first and does not catch an exception.
     # One could try and tell Obs to check if the y in __mul__ is a Corr and
 
+    __array_priority__ = 10000
+
     def __add__(self, y):
         if isinstance(y, Corr):
             if ((self.N != y.N) or (self.T != y.T)):
@@ -1114,7 +1116,23 @@ class Corr:
             return Corr(newcontent)
 
         else:
-            raise TypeError("Matmul not implemented for this type.")
+            return NotImplemented
+
+    def __rmatmul__(self, y):
+        if isinstance(y, np.ndarray):
+            if y.ndim != 2 or y.shape[0] != y.shape[1]:
+                raise ValueError("Can only multiply correlators by square matrices.")
+            if not self.N == y.shape[0]:
+                raise ValueError("matmul: mismatch of matrix dimensions")
+            newcontent = []
+            for t in range(self.T):
+                if _check_for_none(self, self.content[t]):
+                    newcontent.append(None)
+                else:
+                    newcontent.append(y @ self.content[t])
+            return Corr(newcontent)
+        else:
+            return NotImplemented
 
     def __truediv__(self, y):
         if isinstance(y, Corr):