diff --git a/arcade/gl/backends/opengl/context.py b/arcade/gl/backends/opengl/context.py
index 2a7753d253..24f34e47a3 100644
--- a/arcade/gl/backends/opengl/context.py
+++ b/arcade/gl/backends/opengl/context.py
@@ -143,7 +143,7 @@ def blend_func(self, value: Tuple[int, int] | Tuple[int, int, int, int]):
         elif len(value) == 4:
             gl.glBlendFuncSeparate(*value)
         else:
-            ValueError("blend_func takes a tuple of 2 or 4 values")
+            raise ValueError(f"blend_func takes a tuple of 2 or 4 values, got {len(value)}")
 
     @property
     def front_face(self) -> str: