diff --git a/pineappl_py/src/convolutions.rs b/pineappl_py/src/convolutions.rs
index c7a0f050..57251c37 100644
--- a/pineappl_py/src/convolutions.rs
+++ b/pineappl_py/src/convolutions.rs
@@ -70,6 +70,13 @@ impl PyConv {
             convtype: self.conv.conv_type(),
         }
     }
+
+    /// Return the PID of this convolution.
+    #[getter]
+    #[must_use]
+    pub const fn pid(&self) -> i32 {
+        self.conv.pid()
+    }
 }
 
 /// Register submodule in parent.
diff --git a/pineappl_py/tests/test_fk_table.py b/pineappl_py/tests/test_fk_table.py
index dbf32740..8a7b7cdb 100644
--- a/pineappl_py/tests/test_fk_table.py
+++ b/pineappl_py/tests/test_fk_table.py
@@ -153,6 +153,9 @@ def test_polarized_convolution(
         assert not convolutions[0].conv_type.time_like
         assert not convolutions[1].conv_type.polarized
         assert not convolutions[1].conv_type.time_like
+        # Check that the initial states are protons
+        assert convolutions[0].pid == 2212
+        assert convolutions[1].pid == 2212
 
         # Convolution object of the 1st hadron - Polarized
         h1 = ConvType(polarized=True, time_like=False)
diff --git a/pineappl_py/tests/test_grid.py b/pineappl_py/tests/test_grid.py
index 6a5a88fb..0a1ad2ce 100644
--- a/pineappl_py/tests/test_grid.py
+++ b/pineappl_py/tests/test_grid.py
@@ -340,6 +340,9 @@ def test_polarized_convolution(
         assert not convolutions[0].conv_type.time_like
         assert not convolutions[1].conv_type.polarized
         assert not convolutions[1].conv_type.time_like
+        # Check that the initial states are protons
+        assert convolutions[0].pid == 2212
+        assert convolutions[1].pid == 2212
 
         # Convolution object of the 1st hadron - Polarized
         h1 = ConvType(polarized=True, time_like=False)