diff --git a/libraries/transformer/src/androidTest/java/androidx/media3/transformer/mh/SetHdrEditingTransformationTest.java b/libraries/transformer/src/androidTest/java/androidx/media3/transformer/mh/SetHdrEditingTransformationTest.java
index 8ce23e9469..3d54bc9e72 100644
--- a/libraries/transformer/src/androidTest/java/androidx/media3/transformer/mh/SetHdrEditingTransformationTest.java
+++ b/libraries/transformer/src/androidTest/java/androidx/media3/transformer/mh/SetHdrEditingTransformationTest.java
@@ -174,7 +174,7 @@ public class SetHdrEditingTransformationTest {
         assertThat(exception)
             .hasCauseThat()
             .hasMessageThat()
-            .isEqualTo("Tone-mapping requested but not supported by the decoder");
+            .isEqualTo("Tone-mapping requested but not supported by the decoder.");
       }
       return;
     }
diff --git a/libraries/transformer/src/androidTest/java/androidx/media3/transformer/mh/SetHdrToSdrToneMapTransformationTest.java b/libraries/transformer/src/androidTest/java/androidx/media3/transformer/mh/SetHdrToSdrToneMapTransformationTest.java
index 5479f0e239..4312ac800b 100644
--- a/libraries/transformer/src/androidTest/java/androidx/media3/transformer/mh/SetHdrToSdrToneMapTransformationTest.java
+++ b/libraries/transformer/src/androidTest/java/androidx/media3/transformer/mh/SetHdrToSdrToneMapTransformationTest.java
@@ -90,7 +90,7 @@ public class SetHdrToSdrToneMapTransformationTest {
         assertThat(exception)
             .hasCauseThat()
             .hasMessageThat()
-            .isEqualTo("Tone-mapping requested but not supported by the decoder");
+            .isEqualTo("Tone-mapping requested but not supported by the decoder.");
       }
       return;
     }
@@ -147,7 +147,7 @@ public class SetHdrToSdrToneMapTransformationTest {
         assertThat(exception)
             .hasCauseThat()
             .hasMessageThat()
-            .isEqualTo("Tone-mapping requested but not supported by the decoder");
+            .isEqualTo("Tone-mapping requested but not supported by the decoder.");
       }
       return;
     }
diff --git a/libraries/transformer/src/main/java/androidx/media3/transformer/DefaultCodec.java b/libraries/transformer/src/main/java/androidx/media3/transformer/DefaultCodec.java
index 3fd94628b8..baa1884600 100644
--- a/libraries/transformer/src/main/java/androidx/media3/transformer/DefaultCodec.java
+++ b/libraries/transformer/src/main/java/androidx/media3/transformer/DefaultCodec.java
@@ -116,7 +116,7 @@ public final class DefaultCodec implements Codec {
         // https://developer.android.com/reference/android/media/MediaFormat#KEY_COLOR_TRANSFER_REQUEST.
         checkArgument(
             Api29.isSdrToneMappingEnabled(mediaCodec.getInputFormat()),
-            "Tone-mapping requested but not supported by the decoder");
+            "Tone-mapping requested but not supported by the decoder.");
       }
       if (isVideo && !isDecoder) {
         inputSurface = mediaCodec.createInputSurface();