diff --git a/tests/gcm/test_auto.py b/tests/gcm/test_auto.py
index 1e28231087..26fe2df9a8 100644
--- a/tests/gcm/test_auto.py
+++ b/tests/gcm/test_auto.py
@@ -41,7 +41,9 @@ def _generate_non_linear_regression_data():
 
 
 def _generate_linear_classification_data():
-    X = np.random.normal(0, 1, (100, 5))
+    # 500 samples instead of 100 to give cross-validation a stable enough signal
+    # so that LogisticRegression reliably wins over SVC for linear data.
+    X = np.random.normal(0, 1, (500, 5))
     Y = (np.sum(X * np.random.uniform(-5, 5, X.shape[1]), axis=1) > 0).astype(str)
 
     return X, Y