diff --git a/graphics/common/aidl/aidl_api/android.hardware.graphics.common/current/android/hardware/graphics/common/HardwareBufferDescription.aidl b/graphics/common/aidl/aidl_api/android.hardware.graphics.common/current/android/hardware/graphics/common/HardwareBufferDescription.aidl
index 8b1216948b..232e0231f1 100644
--- a/graphics/common/aidl/aidl_api/android.hardware.graphics.common/current/android/hardware/graphics/common/HardwareBufferDescription.aidl
+++ b/graphics/common/aidl/aidl_api/android.hardware.graphics.common/current/android/hardware/graphics/common/HardwareBufferDescription.aidl
@@ -21,7 +21,7 @@ parcelable HardwareBufferDescription {
   int width;
   int height;
   int layers;
-  android.hardware.graphics.common.PixelFormat format;
-  android.hardware.graphics.common.BufferUsage usage;
+  android.hardware.graphics.common.PixelFormat format = android.hardware.graphics.common.PixelFormat.UNSPECIFIED;
+  android.hardware.graphics.common.BufferUsage usage = android.hardware.graphics.common.BufferUsage.CPU_READ_NEVER;
   int stride;
 }
diff --git a/graphics/common/aidl/android/hardware/graphics/common/HardwareBufferDescription.aidl b/graphics/common/aidl/android/hardware/graphics/common/HardwareBufferDescription.aidl
index e1e3492376..078c5126fa 100644
--- a/graphics/common/aidl/android/hardware/graphics/common/HardwareBufferDescription.aidl
+++ b/graphics/common/aidl/android/hardware/graphics/common/HardwareBufferDescription.aidl
@@ -29,7 +29,7 @@ parcelable HardwareBufferDescription {
     int width;
     int height;
     int layers;
-    PixelFormat format;
-    BufferUsage usage;
+    PixelFormat format = PixelFormat.UNSPECIFIED;
+    BufferUsage usage = BufferUsage.CPU_READ_NEVER;
     int stride;
 }
diff --git a/keymaster/aidl/aidl_api/android.hardware.keymaster/current/android/hardware/keymaster/HardwareAuthToken.aidl b/keymaster/aidl/aidl_api/android.hardware.keymaster/current/android/hardware/keymaster/HardwareAuthToken.aidl
index db1df2b050..4f21cba106 100644
--- a/keymaster/aidl/aidl_api/android.hardware.keymaster/current/android/hardware/keymaster/HardwareAuthToken.aidl
+++ b/keymaster/aidl/aidl_api/android.hardware.keymaster/current/android/hardware/keymaster/HardwareAuthToken.aidl
@@ -21,7 +21,7 @@ parcelable HardwareAuthToken {
   long challenge;
   long userId;
   long authenticatorId;
-  android.hardware.keymaster.HardwareAuthenticatorType authenticatorType;
+  android.hardware.keymaster.HardwareAuthenticatorType authenticatorType = android.hardware.keymaster.HardwareAuthenticatorType.NONE;
   android.hardware.keymaster.Timestamp timestamp;
   byte[] mac;
 }
diff --git a/keymaster/aidl/aidl_api/android.hardware.keymaster/current/android/hardware/keymaster/VerificationToken.aidl b/keymaster/aidl/aidl_api/android.hardware.keymaster/current/android/hardware/keymaster/VerificationToken.aidl
index 0633765cac..b116dac925 100644
--- a/keymaster/aidl/aidl_api/android.hardware.keymaster/current/android/hardware/keymaster/VerificationToken.aidl
+++ b/keymaster/aidl/aidl_api/android.hardware.keymaster/current/android/hardware/keymaster/VerificationToken.aidl
@@ -20,6 +20,6 @@ package android.hardware.keymaster;
 parcelable VerificationToken {
   long challenge;
   android.hardware.keymaster.Timestamp timestamp;
-  android.hardware.keymaster.SecurityLevel securityLevel;
+  android.hardware.keymaster.SecurityLevel securityLevel = android.hardware.keymaster.SecurityLevel.SOFTWARE;
   byte[] mac;
 }
diff --git a/keymaster/aidl/android/hardware/keymaster/HardwareAuthToken.aidl b/keymaster/aidl/android/hardware/keymaster/HardwareAuthToken.aidl
index 58602aaa49..99b036aefe 100644
--- a/keymaster/aidl/android/hardware/keymaster/HardwareAuthToken.aidl
+++ b/keymaster/aidl/android/hardware/keymaster/HardwareAuthToken.aidl
@@ -55,7 +55,7 @@ parcelable HardwareAuthToken {
      * authenticatorType describes the type of authentication that took place, e.g. password or
      * fingerprint.
      */
-    HardwareAuthenticatorType authenticatorType;
+    HardwareAuthenticatorType authenticatorType = HardwareAuthenticatorType.NONE;
 
     /**
      * timestamp indicates when the user authentication took place, in milliseconds since some
diff --git a/keymaster/aidl/android/hardware/keymaster/VerificationToken.aidl b/keymaster/aidl/android/hardware/keymaster/VerificationToken.aidl
index f0532543c2..5efd937f38 100644
--- a/keymaster/aidl/android/hardware/keymaster/VerificationToken.aidl
+++ b/keymaster/aidl/android/hardware/keymaster/VerificationToken.aidl
@@ -43,7 +43,7 @@ parcelable VerificationToken {
     /**
      * SecurityLevel of the secure environment that generated the token.
      */
-    SecurityLevel securityLevel;
+    SecurityLevel securityLevel = SecurityLevel.SOFTWARE;
 
     /**
      * 32-byte HMAC-SHA256 of the above values, computed as:
diff --git a/neuralnetworks/aidl/aidl_api/android.hardware.neuralnetworks/current/android/hardware/neuralnetworks/Operand.aidl b/neuralnetworks/aidl/aidl_api/android.hardware.neuralnetworks/current/android/hardware/neuralnetworks/Operand.aidl
index 5a9f4ffc72..1d9bdd8446 100644
--- a/neuralnetworks/aidl/aidl_api/android.hardware.neuralnetworks/current/android/hardware/neuralnetworks/Operand.aidl
+++ b/neuralnetworks/aidl/aidl_api/android.hardware.neuralnetworks/current/android/hardware/neuralnetworks/Operand.aidl
@@ -34,11 +34,11 @@
 package android.hardware.neuralnetworks;
 @VintfStability
 parcelable Operand {
-  android.hardware.neuralnetworks.OperandType type;
+  android.hardware.neuralnetworks.OperandType type = android.hardware.neuralnetworks.OperandType.FLOAT32;
   int[] dimensions;
   float scale;
   int zeroPoint;
-  android.hardware.neuralnetworks.OperandLifeTime lifetime;
+  android.hardware.neuralnetworks.OperandLifeTime lifetime = android.hardware.neuralnetworks.OperandLifeTime.TEMPORARY_VARIABLE;
   android.hardware.neuralnetworks.DataLocation location;
   @nullable android.hardware.neuralnetworks.OperandExtraParams extraParams;
 }
diff --git a/neuralnetworks/aidl/aidl_api/android.hardware.neuralnetworks/current/android/hardware/neuralnetworks/OperandPerformance.aidl b/neuralnetworks/aidl/aidl_api/android.hardware.neuralnetworks/current/android/hardware/neuralnetworks/OperandPerformance.aidl
index de93d8b444..ebb361b762 100644
--- a/neuralnetworks/aidl/aidl_api/android.hardware.neuralnetworks/current/android/hardware/neuralnetworks/OperandPerformance.aidl
+++ b/neuralnetworks/aidl/aidl_api/android.hardware.neuralnetworks/current/android/hardware/neuralnetworks/OperandPerformance.aidl
@@ -34,6 +34,6 @@
 package android.hardware.neuralnetworks;
 @VintfStability
 parcelable OperandPerformance {
-  android.hardware.neuralnetworks.OperandType type;
+  android.hardware.neuralnetworks.OperandType type = android.hardware.neuralnetworks.OperandType.FLOAT32;
   android.hardware.neuralnetworks.PerformanceInfo info;
 }
diff --git a/neuralnetworks/aidl/aidl_api/android.hardware.neuralnetworks/current/android/hardware/neuralnetworks/Operation.aidl b/neuralnetworks/aidl/aidl_api/android.hardware.neuralnetworks/current/android/hardware/neuralnetworks/Operation.aidl
index 33fcd60abc..a4a3fbee60 100644
--- a/neuralnetworks/aidl/aidl_api/android.hardware.neuralnetworks/current/android/hardware/neuralnetworks/Operation.aidl
+++ b/neuralnetworks/aidl/aidl_api/android.hardware.neuralnetworks/current/android/hardware/neuralnetworks/Operation.aidl
@@ -34,7 +34,7 @@
 package android.hardware.neuralnetworks;
 @VintfStability
 parcelable Operation {
-  android.hardware.neuralnetworks.OperationType type;
+  android.hardware.neuralnetworks.OperationType type = android.hardware.neuralnetworks.OperationType.ADD;
   int[] inputs;
   int[] outputs;
 }
diff --git a/neuralnetworks/aidl/android/hardware/neuralnetworks/Operand.aidl b/neuralnetworks/aidl/android/hardware/neuralnetworks/Operand.aidl
index 4d2260feb2..998e06dd34 100644
--- a/neuralnetworks/aidl/android/hardware/neuralnetworks/Operand.aidl
+++ b/neuralnetworks/aidl/android/hardware/neuralnetworks/Operand.aidl
@@ -33,7 +33,7 @@ parcelable Operand {
      * {@link IDevice::OPERAND_TYPE_BASE_MAX} is possible and should be interpreted as an extension
      * type according to {@link Model::extensionNameToPrefix}.
      */
-    OperandType type;
+    OperandType type = OperandType.FLOAT32;
     /**
      * Dimensions of the operand.
      *
@@ -86,7 +86,7 @@ parcelable Operand {
     /**
      * How the operand is used.
      */
-    OperandLifeTime lifetime;
+    OperandLifeTime lifetime = OperandLifeTime.TEMPORARY_VARIABLE;
     /**
      * Where to find the data for this operand.
      * If the lifetime is TEMPORARY_VARIABLE, SUBGRAPH_INPUT, SUBGRAPH_OUTPUT, or NO_VALUE:
diff --git a/neuralnetworks/aidl/android/hardware/neuralnetworks/OperandPerformance.aidl b/neuralnetworks/aidl/android/hardware/neuralnetworks/OperandPerformance.aidl
index 7fd86f90a0..7f53967045 100644
--- a/neuralnetworks/aidl/android/hardware/neuralnetworks/OperandPerformance.aidl
+++ b/neuralnetworks/aidl/android/hardware/neuralnetworks/OperandPerformance.aidl
@@ -25,6 +25,6 @@ import android.hardware.neuralnetworks.PerformanceInfo;
  */
 @VintfStability
 parcelable OperandPerformance {
-    OperandType type;
+    OperandType type = OperandType.FLOAT32;
     PerformanceInfo info;
 }
diff --git a/neuralnetworks/aidl/android/hardware/neuralnetworks/Operation.aidl b/neuralnetworks/aidl/android/hardware/neuralnetworks/Operation.aidl
index 0c6032f625..366d9a4586 100644
--- a/neuralnetworks/aidl/android/hardware/neuralnetworks/Operation.aidl
+++ b/neuralnetworks/aidl/android/hardware/neuralnetworks/Operation.aidl
@@ -30,7 +30,7 @@ parcelable Operation {
      * {@link IDevice::OPERATION_TYPE_BASE_MAX} is possible and should be interpreted as an
      * extension type according to {@link Model::extensionNameToPrefix}.
      */
-    OperationType type;
+    OperationType type = OperationType.ADD;
     /**
      * Describes the table that contains the indexes of the inputs of the operation. The offset is
      * the index in the operandIndexes table.
diff --git a/vibrator/aidl/aidl_api/android.hardware.vibrator/current/android/hardware/vibrator/CompositeEffect.aidl b/vibrator/aidl/aidl_api/android.hardware.vibrator/current/android/hardware/vibrator/CompositeEffect.aidl
index 3be58a1490..679c82cc3b 100644
--- a/vibrator/aidl/aidl_api/android.hardware.vibrator/current/android/hardware/vibrator/CompositeEffect.aidl
+++ b/vibrator/aidl/aidl_api/android.hardware.vibrator/current/android/hardware/vibrator/CompositeEffect.aidl
@@ -35,6 +35,6 @@ package android.hardware.vibrator;
 @VintfStability
 parcelable CompositeEffect {
   int delayMs;
-  android.hardware.vibrator.CompositePrimitive primitive;
+  android.hardware.vibrator.CompositePrimitive primitive = android.hardware.vibrator.CompositePrimitive.NOOP;
   float scale;
 }
diff --git a/vibrator/aidl/android/hardware/vibrator/CompositeEffect.aidl b/vibrator/aidl/android/hardware/vibrator/CompositeEffect.aidl
index 406a899823..5a990c08f8 100644
--- a/vibrator/aidl/android/hardware/vibrator/CompositeEffect.aidl
+++ b/vibrator/aidl/android/hardware/vibrator/CompositeEffect.aidl
@@ -22,7 +22,7 @@ import android.hardware.vibrator.CompositePrimitive;
 parcelable CompositeEffect {
     /* Period of silence preceding primitive. */
     int delayMs;
-    CompositePrimitive primitive;
+    CompositePrimitive primitive = CompositePrimitive.NOOP;
     /*
      * 0.0 (inclusive) - 1.0 (inclusive),
      * where 0.0 is minimum "feelable" amplitude.