diff --git a/pkg/apis/pipeline/v1alpha1/stepaction_validation_test.go b/pkg/apis/pipeline/v1alpha1/stepaction_validation_test.go
index 2aa9a51a4ee..98583cc4917 100644
--- a/pkg/apis/pipeline/v1alpha1/stepaction_validation_test.go
+++ b/pkg/apis/pipeline/v1alpha1/stepaction_validation_test.go
@@ -572,6 +572,69 @@ func TestStepActionValidateError(t *testing.T) {
 			Message: `non-existent variable in "$(params.gitrepo.foo)"`,
 			Paths:   []string{"spec.volumeMounts[0]"},
 		},
+	}, {
+		name: "circular dependency in param default values",
+		fields: fields{
+			Image: "myimage",
+			Params: []v1.ParamSpec{{
+				Name:    "param1",
+				Type:    v1.ParamTypeString,
+				Default: v1.NewStructuredValues("$(params.param2)"),
+			}, {
+				Name:    "param2",
+				Type:    v1.ParamTypeString,
+				Default: v1.NewStructuredValues("$(params.param1)"),
+			}},
+		},
+		expectedError: *((&apis.FieldError{
+			Message: `param "param1" default value has a circular dependency`,
+			Paths:   []string{"spec.params"},
+		}).Also(&apis.FieldError{
+			Message: `param "param2" default value has a circular dependency`,
+			Paths:   []string{"spec.params"},
+		})),
+	}, {
+		name: "complex circular dependency in param default values",
+		fields: fields{
+			Image: "myimage",
+			Params: []v1.ParamSpec{{
+				Name:    "param1",
+				Type:    v1.ParamTypeString,
+				Default: v1.NewStructuredValues("$(params.param2)"),
+			}, {
+				Name:    "param2",
+				Type:    v1.ParamTypeString,
+				Default: v1.NewStructuredValues("$(params.param3)"),
+			}, {
+				Name:    "param3",
+				Type:    v1.ParamTypeString,
+				Default: v1.NewStructuredValues("$(params.param1)"),
+			}},
+		},
+		expectedError: *((&apis.FieldError{
+			Message: `param "param1" default value has a circular dependency`,
+			Paths:   []string{"spec.params"},
+		}).Also(&apis.FieldError{
+			Message: `param "param2" default value has a circular dependency`,
+			Paths:   []string{"spec.params"},
+		}).Also(&apis.FieldError{
+			Message: `param "param3" default value has a circular dependency`,
+			Paths:   []string{"spec.params"},
+		})),
+	}, {
+		name: "self-referential param default value",
+		fields: fields{
+			Image: "myimage",
+			Params: []v1.ParamSpec{{
+				Name:    "param1",
+				Type:    v1.ParamTypeString,
+				Default: v1.NewStructuredValues("$(params.param1)"),
+			}},
+		},
+		expectedError: apis.FieldError{
+			Message: `param "param1" default value has a circular dependency`,
+			Paths:   []string{"spec.params"},
+		},
 	}}
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
@@ -594,6 +657,7 @@ func TestStepActionValidateError(t *testing.T) {
 			if err == nil {
 				t.Fatalf("Expected an error, got nothing for %v", sa)
 			}
+			t.Logf("Actual error: %v", err)
 			if d := cmp.Diff(tt.expectedError.Error(), err.Error(), cmpopts.IgnoreUnexported(apis.FieldError{})); d != "" {
 				t.Errorf("StepActionSpec.Validate() errors diff %s", diff.PrintWantGot(d))
 			}
@@ -1013,6 +1077,7 @@ func TestStepActionSpecValidateError(t *testing.T) {
 			if err == nil {
 				t.Fatalf("Expected an error, got nothing for %v", sa)
 			}
+			t.Logf("Actual error: %v", err)
 			if d := cmp.Diff(tt.expectedError.Error(), err.Error(), cmpopts.IgnoreUnexported(apis.FieldError{})); d != "" {
 				t.Errorf("StepActionSpec.Validate() errors diff %s", diff.PrintWantGot(d))
 			}