diff --git a/compatibility_matrices/compatibility_matrix.3.xml b/compatibility_matrices/compatibility_matrix.3.xml
index 608890bcf1..a75ed25f1d 100644
--- a/compatibility_matrices/compatibility_matrix.3.xml
+++ b/compatibility_matrices/compatibility_matrix.3.xml
@@ -223,7 +223,7 @@
             <instance>default</instance>
         </interface>
     </hal>
-    <hal format="hidl" optional="false">
+    <hal format="hidl" optional="true">
         <name>android.hardware.keymaster</name>
         <version>3.0</version>
         <version>4.0</version>
diff --git a/compatibility_matrices/compatibility_matrix.4.xml b/compatibility_matrices/compatibility_matrix.4.xml
index e5e012cbb3..3b8ee2198e 100644
--- a/compatibility_matrices/compatibility_matrix.4.xml
+++ b/compatibility_matrices/compatibility_matrix.4.xml
@@ -245,7 +245,7 @@
             <instance>default</instance>
         </interface>
     </hal>
-    <hal format="hidl" optional="false">
+    <hal format="hidl" optional="true">
         <name>android.hardware.keymaster</name>
         <version>3.0</version>
         <version>4.0</version>
diff --git a/compatibility_matrices/compatibility_matrix.5.xml b/compatibility_matrices/compatibility_matrix.5.xml
index 8e175f02d7..0fb21a7443 100644
--- a/compatibility_matrices/compatibility_matrix.5.xml
+++ b/compatibility_matrices/compatibility_matrix.5.xml
@@ -284,7 +284,7 @@
             <instance>default</instance>
         </interface>
     </hal>
-    <hal format="hidl" optional="false">
+    <hal format="hidl" optional="true">
         <name>android.hardware.keymaster</name>
         <version>3.0</version>
         <version>4.0-1</version>
diff --git a/compatibility_matrices/compatibility_matrix.current.xml b/compatibility_matrices/compatibility_matrix.current.xml
index 30af25f1f9..039ea846f0 100644
--- a/compatibility_matrices/compatibility_matrix.current.xml
+++ b/compatibility_matrices/compatibility_matrix.current.xml
@@ -297,7 +297,7 @@
             <instance>default</instance>
         </interface>
     </hal>
-    <hal format="hidl" optional="false">
+    <hal format="hidl" optional="true">
         <name>android.hardware.keymaster</name>
         <version>3.0</version>
         <version>4.0-1</version>