diff --git a/compatibility_matrices/compatibility_matrix.6.xml b/compatibility_matrices/compatibility_matrix.6.xml
index e19d2dd..40ae655 100644
--- a/compatibility_matrices/compatibility_matrix.6.xml
+++ b/compatibility_matrices/compatibility_matrix.6.xml
@@ -7,7 +7,7 @@
             <instance>default</instance>
         </interface>
     </hal>
-    <hal format="hidl" optional="false">
+    <hal format="hidl" optional="true">
         <name>android.hardware.audio</name>
         <version>6.0</version>
         <version>7.0</version>
@@ -16,7 +16,7 @@
             <instance>default</instance>
         </interface>
     </hal>
-    <hal format="hidl" optional="false">
+    <hal format="hidl" optional="true">
         <name>android.hardware.audio.effect</name>
         <version>6.0</version>
         <version>7.0</version>
@@ -215,7 +215,7 @@
             <instance>default</instance>
         </interface>
     </hal>
-    <hal format="hidl" optional="false">
+    <hal format="hidl" optional="true">
         <name>android.hardware.gatekeeper</name>
         <version>1.0</version>
         <interface>
@@ -252,7 +252,7 @@
             <instance>default</instance>
         </interface>
     </hal>
-    <hal format="hidl" optional="false">
+    <hal format="hidl" optional="true">
         <name>android.hardware.graphics.composer</name>
         <version>2.1-4</version>
         <interface>
@@ -260,7 +260,7 @@
             <instance>default</instance>
         </interface>
     </hal>
-    <hal format="hidl" optional="false">
+    <hal format="hidl" optional="true">
         <name>android.hardware.graphics.mapper</name>
         <!-- New, non-Go devices should use 4.0, tested in vts_treble_vintf_vendor_test -->
         <version>2.1</version>
@@ -423,7 +423,7 @@
             <instance>default</instance>
         </interface>
     </hal>
-    <hal format="aidl" optional="false">
+    <hal format="aidl" optional="true">
         <name>android.hardware.power</name>
         <version>1-2</version>
         <interface>