diff --git a/provider_tekton.go b/provider_tekton.go
index d886f68..ce39c7c 100644
--- a/provider_tekton.go
+++ b/provider_tekton.go
@@ -368,7 +368,9 @@ func buildTektonPipelineRun(
 	}
 
 	if cfg.ServiceAccount != "" {
-		spec["serviceAccountName"] = cfg.ServiceAccount
+		spec["taskRunTemplate"] = map[string]any{
+			"serviceAccountName": cfg.ServiceAccount,
+		}
 	}
 
 	// Merge user-defined params with the built-in ones (commit,
diff --git a/provider_tekton_test.go b/provider_tekton_test.go
index 2fbe56b..a4ccd67 100644
--- a/provider_tekton_test.go
+++ b/provider_tekton_test.go
@@ -113,7 +113,7 @@ func TestTektonBuildPipelineRun(t *testing.T) {
 	if !ok || pipeline != "repo-ci" {
 		t.Fatalf("pipelineRef.name = %q", pipeline)
 	}
-	sa, ok := obj.NestedString("spec", "serviceAccountName")
+	sa, ok := obj.NestedString("spec", "taskRunTemplate", "serviceAccountName")
 	if !ok || sa != "runner" {
 		t.Fatalf("serviceAccountName = %q", sa)
 	}