diff --git a/compatibility_matrices/compatibility_matrix.7.xml b/compatibility_matrices/compatibility_matrix.7.xml
index 26b8d63..c267516 100644
--- a/compatibility_matrices/compatibility_matrix.7.xml
+++ b/compatibility_matrices/compatibility_matrix.7.xml
@@ -682,7 +682,7 @@
             <instance>default</instance>
         </interface>
     </hal>
-    <hal format="hidl" optional="false">
+    <hal format="hidl" optional="true">
         <name>android.hardware.thermal</name>
         <version>2.0</version>
         <interface>
diff --git a/compatibility_matrices/compatibility_matrix.8.xml b/compatibility_matrices/compatibility_matrix.8.xml
index 64bfc7a..e320734 100644
--- a/compatibility_matrices/compatibility_matrix.8.xml
+++ b/compatibility_matrices/compatibility_matrix.8.xml
@@ -692,7 +692,7 @@
             <instance>default</instance>
         </interface>
     </hal>
-    <hal format="aidl" optional="false">
+    <hal format="aidl" optional="true">
         <name>android.hardware.thermal</name>
         <version>1</version>
         <interface>