diff --git a/extensions/ima/src/main/java/com/google/android/exoplayer2/ext/ima/ImaServerSideAdInsertionUriBuilder.java b/extensions/ima/src/main/java/com/google/android/exoplayer2/ext/ima/ImaServerSideAdInsertionUriBuilder.java
index 1334a488a2..8586bac989 100644
--- a/extensions/ima/src/main/java/com/google/android/exoplayer2/ext/ima/ImaServerSideAdInsertionUriBuilder.java
+++ b/extensions/ima/src/main/java/com/google/android/exoplayer2/ext/ima/ImaServerSideAdInsertionUriBuilder.java
@@ -366,6 +366,10 @@ public final class ImaServerSideAdInsertionUriBuilder {
     if (streamActivityMonitorId != null) {
       streamRequest.setStreamActivityMonitorId(streamActivityMonitorId);
     }
+    checkState(
+        streamRequest.getFormat() != StreamFormat.DASH
+            || TextUtils.isEmpty(streamRequest.getAssetKey()),
+        "DASH live streams are not supported yet.");
     return streamRequest;
   }
 }