diff --git a/app/src/main/java/com/battlelancer/seriesguide/settings/TmdbSettings.kt b/app/src/main/java/com/battlelancer/seriesguide/settings/TmdbSettings.kt
index 8b95e7e63e..8af3c9741b 100644
--- a/app/src/main/java/com/battlelancer/seriesguide/settings/TmdbSettings.kt
+++ b/app/src/main/java/com/battlelancer/seriesguide/settings/TmdbSettings.kt
@@ -18,12 +18,12 @@ object TmdbSettings {
      week, updating weekly should be fine. */
     private const val UPDATE_INTERVAL_MS = 7 * DateUtils.DAY_IN_MILLIS
 
-    const val KEY_TMDB_BASE_URL = "com.battlelancer.seriesguide.tmdb.baseurl"
+    private const val KEY_TMDB_BASE_URL = "com.battlelancer.seriesguide.tmdb.baseurl"
     const val POSTER_SIZE_SPEC_W154 = "w154"
     const val POSTER_SIZE_SPEC_W342 = "w342"
     private const val STILL_SIZE_SPEC_W300 = "w300"
-    const val IMAGE_SIZE_SPEC_ORIGINAL = "original"
-    private const val DEFAULT_BASE_URL = "https://image.tmdb.org/t/p/"
+    private const val IMAGE_SIZE_SPEC_ORIGINAL = "original"
+    const val DEFAULT_BASE_URL = "https://image.tmdb.org/t/p/"
 
     fun isConfigurationUpToDate(context: Context): Boolean {
         val lastUpdatedMs =
@@ -37,6 +37,16 @@ object TmdbSettings {
         }
     }
 
+    /**
+     * Saves the base URL, unless it's empty or blank.
+     */
+    fun setImageBaseUrl(context: Context, url: String) {
+        if (url.isEmpty() || url.isBlank()) return
+        PreferenceManager.getDefaultSharedPreferences(context).edit {
+            putString(KEY_TMDB_BASE_URL, url)
+        }
+    }
+
     @JvmStatic
     fun getImageBaseUrl(context: Context): String {
         return PreferenceManager.getDefaultSharedPreferences(context)
diff --git a/app/src/main/java/com/battlelancer/seriesguide/sync/SgSyncAdapter.kt b/app/src/main/java/com/battlelancer/seriesguide/sync/SgSyncAdapter.kt
index 6bc68ee3d6..930277add8 100644
--- a/app/src/main/java/com/battlelancer/seriesguide/sync/SgSyncAdapter.kt
+++ b/app/src/main/java/com/battlelancer/seriesguide/sync/SgSyncAdapter.kt
@@ -107,7 +107,7 @@ class SgSyncAdapter(context: Context) : AbstractThreadedSyncAdapter(context, tru
         // Get latest TMDb configuration.
         val tmdbSync = TmdbSync(context, tmdbConfigService.get(), movieTools.get())
         val prefs = PreferenceManager.getDefaultSharedPreferences(context)
-        tmdbSync.updateConfigurationAndWatchProviders(progress, prefs)
+        tmdbSync.updateConfigurationAndWatchProviders(progress)
 
         // Update show data.
         // If failed for at least one show, do not proceed with other sync steps to avoid
diff --git a/app/src/main/java/com/battlelancer/seriesguide/sync/TmdbSync.kt b/app/src/main/java/com/battlelancer/seriesguide/sync/TmdbSync.kt
index be8d9afc71..ec04c2c9ff 100644
--- a/app/src/main/java/com/battlelancer/seriesguide/sync/TmdbSync.kt
+++ b/app/src/main/java/com/battlelancer/seriesguide/sync/TmdbSync.kt
@@ -4,9 +4,7 @@
 package com.battlelancer.seriesguide.sync
 
 import android.content.Context
-import android.content.SharedPreferences
 import android.text.format.DateUtils
-import androidx.core.content.edit
 import com.battlelancer.seriesguide.movies.MoviesSettings
 import com.battlelancer.seriesguide.movies.tools.MovieTools
 import com.battlelancer.seriesguide.provider.SgRoomDatabase
@@ -25,7 +23,7 @@ class TmdbSync internal constructor(
     private val movieTools: MovieTools
 ) {
 
-    fun updateConfigurationAndWatchProviders(progress: SyncProgress, prefs: SharedPreferences) {
+    fun updateConfigurationAndWatchProviders(progress: SyncProgress) {
         if (TmdbSettings.isConfigurationUpToDate(context)) {
             return
         }
@@ -33,7 +31,7 @@ class TmdbSync internal constructor(
         var hadError = false
 
         // Image URL configuration
-        if (!updateConfiguration(prefs)) {
+        if (!updateConfiguration()) {
             hadError = true
         }
 
@@ -59,15 +57,14 @@ class TmdbSync internal constructor(
     /**
      * Downloads and stores the latest image url configuration from themoviedb.org.
      */
-    private fun updateConfiguration(prefs: SharedPreferences): Boolean {
+    private fun updateConfiguration(): Boolean {
         try {
             val response = configurationService.configuration().execute()
             if (response.isSuccessful) {
                 val config = response.body()
-                if (!config?.images?.secure_base_url.isNullOrEmpty()) {
-                    prefs.edit {
-                        putString(TmdbSettings.KEY_TMDB_BASE_URL, config!!.images!!.secure_base_url)
-                    }
+                val baseUrl = config?.images?.secure_base_url
+                if (baseUrl != null) {
+                    TmdbSettings.setImageBaseUrl(context, baseUrl)
                     return true
                 }
             } else {
diff --git a/app/src/test/java/com/battlelancer/seriesguide/settings/TmdbSettingsTest.kt b/app/src/test/java/com/battlelancer/seriesguide/settings/TmdbSettingsTest.kt
index 57d370c231..95cc14b034 100644
--- a/app/src/test/java/com/battlelancer/seriesguide/settings/TmdbSettingsTest.kt
+++ b/app/src/test/java/com/battlelancer/seriesguide/settings/TmdbSettingsTest.kt
@@ -26,4 +26,19 @@ class TmdbSettingsTest {
         assertThat(TmdbSettings.isConfigurationUpToDate(context)).isTrue()
     }
 
+    @Test
+    fun getImageBaseUrl() {
+        assertThat(TmdbSettings.getImageBaseUrl(context)).isEqualTo(TmdbSettings.DEFAULT_BASE_URL)
+
+        TmdbSettings.setImageBaseUrl(context, "")
+        assertThat(TmdbSettings.getImageBaseUrl(context)).isEqualTo(TmdbSettings.DEFAULT_BASE_URL)
+
+        TmdbSettings.setImageBaseUrl(context, "   ")
+        assertThat(TmdbSettings.getImageBaseUrl(context)).isEqualTo(TmdbSettings.DEFAULT_BASE_URL)
+
+        val testValue = "placeholder"
+        TmdbSettings.setImageBaseUrl(context, testValue)
+        assertThat(TmdbSettings.getImageBaseUrl(context)).isEqualTo(testValue)
+    }
+
 }
\ No newline at end of file