diff --git a/tmu/lib/src/ClauseBank.c b/tmu/lib/src/ClauseBank.c
index e8b9bd97..36f9b5d5 100644
--- a/tmu/lib/src/ClauseBank.c
+++ b/tmu/lib/src/ClauseBank.c
@@ -1627,6 +1627,13 @@ void cb_calculate_spatio_temporal_features(
 					&Xi[patch*number_of_ta_chunks],
 					0
 				);
+
+				unsigned int patch_chunk = patch / 32;
+				unsigned int patch_pos = patch % 32;
+
+				if (((clause_node_output[j*number_of_patch_chunks + patch_chunk] & (1 << patch_pos)) > 0) != clause_value_in_patch[patch] ) {
+					printf("ERROR %d %d %d %d %d %d\n", j, patch, patch_chunk, patch_pos, (clause_node_output[j*number_of_patch_chunks + patch_chunk] & (1 << patch_pos)) > 0, clause_value_in_patch[patch]);
+				}
 			}
 
 			for (int patch = 0; patch < number_of_patches; ++patch) {