diff --git a/algo/algo_test.go b/algo/algo_test.go
index 38322aa..8434e3b 100644
--- a/algo/algo_test.go
+++ b/algo/algo_test.go
@@ -25,6 +25,12 @@ func TestDoRandomSearchExec(t *testing.T) {
 	if err := os.RemoveAll(picsDir); err != nil {
 		t.Error(err)
 	}
+
+	// if `stat` on picsDir succeeds now, something is wrong (namely the
+	// clean-up apparently did not succeed).
+	if _, err := os.Stat(picsDir); err == nil {
+		t.Error("picsDir should have already been cleaned up")
+	}
 }
 
 func TestDoSHCExec(t *testing.T) {
@@ -39,6 +45,12 @@ func TestDoSHCExec(t *testing.T) {
 	if err := os.RemoveAll(picsDir); err != nil {
 		t.Error(err)
 	}
+
+	// if `stat` on picsDir succeeds now, something is wrong (namely the
+	// clean-up apparently did not succeed).
+	if _, err := os.Stat(picsDir); err == nil {
+		t.Error("picsDir should have already been cleaned up")
+	}
 }
 
 func TestNewValues(t *testing.T) {