diff --git a/map2loop/project.py b/map2loop/project.py
index 58f6b5af..c7a1f2db 100644
--- a/map2loop/project.py
+++ b/map2loop/project.py
@@ -357,6 +357,21 @@ def set_sampler(self, datatype: Datatype, sampler: Sampler):
             sampler (Sampler):
                 The sampler to use
         """
+        allowed_samplers = {
+            Datatype.STRUCTURE: SamplerDecimator,
+            Datatype.GEOLOGY: SamplerSpacing,
+            Datatype.FAULT: SamplerSpacing,
+            Datatype.FOLD: SamplerSpacing,
+            Datatype.DTM: SamplerSpacing,
+        }
+
+        # Check for wrong sampler
+        if datatype in allowed_samplers:
+            allowed_sampler_type = allowed_samplers[datatype]
+            if not isinstance(sampler, allowed_sampler_type):
+                raise ValueError(
+                    f"Got wrong argument for this datatype: {type(sampler).__name__}, please use {allowed_sampler_type.__name__} instead"
+                )
         ## does the enum print the number or the label?
         logger.info(f"Setting sampler for {datatype} to {sampler.sampler_label}")
         self.samplers[datatype] = sampler
diff --git a/map2loop/sampler.py b/map2loop/sampler.py
index 01600566..77950b13 100644
--- a/map2loop/sampler.py
+++ b/map2loop/sampler.py
@@ -9,7 +9,7 @@
 import pandas
 import shapely
 import numpy
-from typing import Optional
+from typing import Optional, Union
 
 
 class Sampler(ABC):