diff --git a/src/sage/rings/complex_ball_acb.pyx b/src/sage/rings/complex_ball_acb.pyx
index 0f02528bf5c..8bb56daacb7 100644
--- a/src/sage/rings/complex_ball_acb.pyx
+++ b/src/sage/rings/complex_ball_acb.pyx
@@ -103,6 +103,11 @@ Automatic coercions work as expected::
     sage: bpol/3
     ([0.333333 +/- 4.93e-7])*x + [0.47140 +/- 5.39e-6] + [0.44444 +/- 4.98e-6]*I
 
+TESTS::
+
+    sage: polygen(CBF, x)^3
+    x^3
+
 Classes and Methods
 ===================
 """
diff --git a/src/sage/rings/real_arb.pyx b/src/sage/rings/real_arb.pyx
index e7cc2d0e0ad..b642b648d17 100644
--- a/src/sage/rings/real_arb.pyx
+++ b/src/sage/rings/real_arb.pyx
@@ -121,6 +121,9 @@ TESTS::
     sage: (RBF(pi) * identity_matrix(QQ, 3)).parent()
     Full MatrixSpace of 3 by 3 dense matrices over Real ball field with 53 bits precision
 
+    sage: polygen(RBF, x)^3
+    x^3
+
 Classes and Methods
 ===================
 """