diff --git a/gnss/aidl/aidl_api/android.hardware.gnss/current/android/hardware/gnss/BlocklistedSource.aidl b/gnss/aidl/aidl_api/android.hardware.gnss/current/android/hardware/gnss/BlocklistedSource.aidl
index 11cdcfc..1a2feb7 100644
--- a/gnss/aidl/aidl_api/android.hardware.gnss/current/android/hardware/gnss/BlocklistedSource.aidl
+++ b/gnss/aidl/aidl_api/android.hardware.gnss/current/android/hardware/gnss/BlocklistedSource.aidl
@@ -33,6 +33,6 @@
 package android.hardware.gnss;
 @VintfStability
 parcelable BlocklistedSource {
-  android.hardware.gnss.GnssConstellationType constellation;
+  android.hardware.gnss.GnssConstellationType constellation = android.hardware.gnss.GnssConstellationType.UNKNOWN;
   int svid;
 }
diff --git a/gnss/aidl/aidl_api/android.hardware.gnss/current/android/hardware/gnss/GnssMeasurement.aidl b/gnss/aidl/aidl_api/android.hardware.gnss/current/android/hardware/gnss/GnssMeasurement.aidl
index 728ff68..bc73bb1 100644
--- a/gnss/aidl/aidl_api/android.hardware.gnss/current/android/hardware/gnss/GnssMeasurement.aidl
+++ b/gnss/aidl/aidl_api/android.hardware.gnss/current/android/hardware/gnss/GnssMeasurement.aidl
@@ -50,7 +50,7 @@
   long carrierCycles;
   double carrierPhase;
   double carrierPhaseUncertainty;
-  android.hardware.gnss.GnssMultipathIndicator multipathIndicator;
+  android.hardware.gnss.GnssMultipathIndicator multipathIndicator = android.hardware.gnss.GnssMultipathIndicator.UNKNOWN;
   double snrDb;
   double agcLevelDb;
   double fullInterSignalBiasNs;
diff --git a/gnss/aidl/aidl_api/android.hardware.gnss/current/android/hardware/gnss/GnssSignalType.aidl b/gnss/aidl/aidl_api/android.hardware.gnss/current/android/hardware/gnss/GnssSignalType.aidl
index f729d4c..ba02f72 100644
--- a/gnss/aidl/aidl_api/android.hardware.gnss/current/android/hardware/gnss/GnssSignalType.aidl
+++ b/gnss/aidl/aidl_api/android.hardware.gnss/current/android/hardware/gnss/GnssSignalType.aidl
@@ -33,7 +33,7 @@
 package android.hardware.gnss;
 @VintfStability
 parcelable GnssSignalType {
-  android.hardware.gnss.GnssConstellationType constellation;
+  android.hardware.gnss.GnssConstellationType constellation = android.hardware.gnss.GnssConstellationType.UNKNOWN;
   double carrierFrequencyHz;
   @utf8InCpp String codeType;
   const @utf8InCpp String CODE_TYPE_A = "A";
diff --git a/gnss/aidl/android/hardware/gnss/BlocklistedSource.aidl b/gnss/aidl/android/hardware/gnss/BlocklistedSource.aidl
index 2fde5b2..8b73092 100644
--- a/gnss/aidl/android/hardware/gnss/BlocklistedSource.aidl
+++ b/gnss/aidl/android/hardware/gnss/BlocklistedSource.aidl
@@ -26,7 +26,7 @@
     /**
      * Defines the constellation of the given satellite(s).
      */
-    GnssConstellationType constellation;
+    GnssConstellationType constellation = GnssConstellationType.UNKNOWN;
 
     /**
      * Satellite (space vehicle) ID number, as defined in GnssSvInfo::svid, or 0 to blocklist all
diff --git a/gnss/aidl/android/hardware/gnss/GnssMeasurement.aidl b/gnss/aidl/android/hardware/gnss/GnssMeasurement.aidl
index 4468b63..f20cd25 100644
--- a/gnss/aidl/android/hardware/gnss/GnssMeasurement.aidl
+++ b/gnss/aidl/android/hardware/gnss/GnssMeasurement.aidl
@@ -536,7 +536,7 @@
      * contain multipath, and MULTIPATH_INDICATOR_NOT_PRESENT for those
      * signals that are tracked and do not contain multipath.
      */
-    GnssMultipathIndicator multipathIndicator;
+    GnssMultipathIndicator multipathIndicator = GnssMultipathIndicator.UNKNOWN;
 
     /**
      * Signal-to-noise ratio at correlator output in dB.
diff --git a/gnss/aidl/android/hardware/gnss/GnssSignalType.aidl b/gnss/aidl/android/hardware/gnss/GnssSignalType.aidl
index 9c68db1..a16b170 100644
--- a/gnss/aidl/android/hardware/gnss/GnssSignalType.aidl
+++ b/gnss/aidl/android/hardware/gnss/GnssSignalType.aidl
@@ -26,7 +26,7 @@
     /**
      * Constellation type of the SV that transmits the signal.
      */
-    GnssConstellationType constellation;
+    GnssConstellationType constellation = GnssConstellationType.UNKNOWN;
 
     /**
      * Carrier frequency of the signal tracked, for example it can be the