diff --git a/pkg/oonimkall/session.go b/pkg/oonimkall/session.go
index fdbca43..85c4ed5 100644
--- a/pkg/oonimkall/session.go
+++ b/pkg/oonimkall/session.go
@@ -366,7 +366,7 @@ type CheckInConfig struct {
 
 	// RunType indicates whether this is an automated (model.RunTypeTimed) run
 	// or otherwise a manual run initiated by the user.
-	RunType model.RunType
+	RunType string
 
 	// SoftwareName is the name of the application.
 	SoftwareName string
@@ -472,7 +472,7 @@ func (sess *Session) CheckIn(ctx *Context, config *CheckInConfig) (*CheckInInfo,
 		Platform:        config.Platform,
 		ProbeASN:        info.ASNString(),
 		ProbeCC:         info.CountryCode,
-		RunType:         config.RunType,
+		RunType:         model.RunType(config.RunType),
 		SoftwareVersion: config.SoftwareVersion,
 		WebConnectivity: config.WebConnectivity.toModel(),
 	}
diff --git a/pkg/oonimkall/session_integration_test.go b/pkg/oonimkall/session_integration_test.go
index 70af283..f875084 100644
--- a/pkg/oonimkall/session_integration_test.go
+++ b/pkg/oonimkall/session_integration_test.go
@@ -259,7 +259,7 @@ func TestCheckInSuccess(t *testing.T) {
 		Charging:        true,
 		OnWiFi:          true,
 		Platform:        "android",
-		RunType:         model.RunTypeTimed,
+		RunType:         string(model.RunTypeTimed),
 		SoftwareName:    "ooniprobe-android",
 		SoftwareVersion: "2.7.1",
 		WebConnectivity: &oonimkall.CheckInConfigWebConnectivity{},
@@ -307,7 +307,7 @@ func TestCheckInLookupLocationFailure(t *testing.T) {
 		Charging:        true,
 		OnWiFi:          true,
 		Platform:        "android",
-		RunType:         model.RunTypeTimed,
+		RunType:         string(model.RunTypeTimed),
 		SoftwareName:    "ooniprobe-android",
 		SoftwareVersion: "2.7.1",
 		WebConnectivity: &oonimkall.CheckInConfigWebConnectivity{},
@@ -337,7 +337,7 @@ func TestCheckInNewProbeServicesFailure(t *testing.T) {
 		Charging:        true,
 		OnWiFi:          true,
 		Platform:        "android",
-		RunType:         model.RunTypeTimed,
+		RunType:         string(model.RunTypeTimed),
 		SoftwareName:    "ooniprobe-android",
 		SoftwareVersion: "2.7.1",
 		WebConnectivity: &oonimkall.CheckInConfigWebConnectivity{},
@@ -366,7 +366,7 @@ func TestCheckInCheckInFailure(t *testing.T) {
 		Charging:        true,
 		OnWiFi:          true,
 		Platform:        "android",
-		RunType:         model.RunTypeTimed,
+		RunType:         string(model.RunTypeTimed),
 		SoftwareName:    "ooniprobe-android",
 		SoftwareVersion: "2.7.1",
 		WebConnectivity: &oonimkall.CheckInConfigWebConnectivity{},
@@ -392,7 +392,7 @@ func TestCheckInNoParams(t *testing.T) {
 		Charging:        true,
 		OnWiFi:          true,
 		Platform:        "android",
-		RunType:         model.RunTypeTimed,
+		RunType:         string(model.RunTypeTimed),
 		SoftwareName:    "ooniprobe-android",
 		SoftwareVersion: "2.7.1",
 	}