diff --git a/graphics/mapper/3.0/IMapper.hal b/graphics/mapper/3.0/IMapper.hal
index 0361b7b..b8248e4 100644
--- a/graphics/mapper/3.0/IMapper.hal
+++ b/graphics/mapper/3.0/IMapper.hal
@@ -196,6 +196,12 @@
      * memory. This address will represent the top-left corner of the entire
      * buffer, even if @p accessRegion does not begin at the top-left corner.
      *
+     * On success, bytesPerPixel must contain the number of bytes per pixel in
+     * the buffer. If the bytesPerPixel is unknown or variable, a value of -1
+     * should be returned. bytesPerStride must contain the bytes per stride of
+     * the buffer. If the bytesPerStride is unknown or variable, a value of -1
+     * should be returned.
+     *
      * @param buffer Buffer to lock.
      * @param cpuUsage CPU usage flags to request. See +ndk
      *     libnativewindow#AHardwareBuffer_UsageFlags for possible values.
@@ -214,13 +220,17 @@
      *     - `NO_RESOURCES` if the buffer cannot be locked at this time. Note
      *       that locking may succeed at a later time.
      * @return data CPU-accessible pointer to the buffer data.
+     * @return bytesPerPixel the number of bytes per pixel in the buffer
+     * @return bytesPerStride the number of bytes per stride of the buffer
      */
     lock(pointer buffer,
          uint64_t cpuUsage,
          Rect accessRegion,
          handle acquireFence)
             generates (Error error,
-                       pointer data);
+                       pointer data,
+                       int32_t bytesPerPixel,
+                       int32_t bytesPerStride);
 
     /**
      * Locks a YCbCr buffer for the specified CPU usage.
diff --git a/graphics/mapper/3.0/utils/vts/MapperVts.cpp b/graphics/mapper/3.0/utils/vts/MapperVts.cpp
index 8428403..4b24a1f 100644
--- a/graphics/mapper/3.0/utils/vts/MapperVts.cpp
+++ b/graphics/mapper/3.0/utils/vts/MapperVts.cpp
@@ -164,7 +164,8 @@
 }
 
 void* Gralloc::lock(const native_handle_t* bufferHandle, uint64_t cpuUsage,
-                    const IMapper::Rect& accessRegion, int acquireFence) {
+                    const IMapper::Rect& accessRegion, int acquireFence, int32_t* outBytesPerPixel,
+                    int32_t* outBytesPerStride) {
     auto buffer = const_cast<native_handle_t*>(bufferHandle);
 
     NATIVE_HANDLE_DECLARE_STORAGE(acquireFenceStorage, 1, 0);
@@ -177,9 +178,12 @@
 
     void* data = nullptr;
     mMapper->lock(buffer, cpuUsage, accessRegion, acquireFenceHandle,
-                  [&](const auto& tmpError, const auto& tmpData) {
+                  [&](const auto& tmpError, const auto& tmpData, int32_t tmpBytesPerPixel,
+                      int32_t tmpBytesPerStride) {
                       ASSERT_EQ(Error::NONE, tmpError) << "failed to lock buffer " << buffer;
                       data = tmpData;
+                      *outBytesPerPixel = tmpBytesPerPixel;
+                      *outBytesPerStride = tmpBytesPerStride;
                   });
 
     if (acquireFence >= 0) {
diff --git a/graphics/mapper/3.0/utils/vts/include/mapper-vts/3.0/MapperVts.h b/graphics/mapper/3.0/utils/vts/include/mapper-vts/3.0/MapperVts.h
index c94961c..efae82f 100644
--- a/graphics/mapper/3.0/utils/vts/include/mapper-vts/3.0/MapperVts.h
+++ b/graphics/mapper/3.0/utils/vts/include/mapper-vts/3.0/MapperVts.h
@@ -68,7 +68,8 @@
     // in and out of the mapper.  The ownership of the fd is always transferred
     // with each of these functions.
     void* lock(const native_handle_t* bufferHandle, uint64_t cpuUsage,
-               const IMapper::Rect& accessRegion, int acquireFence);
+               const IMapper::Rect& accessRegion, int acquireFence, int32_t* outBytesPerPixel,
+               int32_t* outBytesPerStride);
     YCbCrLayout lockYCbCr(const native_handle_t* bufferHandle, uint64_t cpuUsage,
                           const IMapper::Rect& accessRegion, int acquireFence);
     int unlock(const native_handle_t* bufferHandle);
diff --git a/graphics/mapper/3.0/vts/functional/VtsHalGraphicsMapperV3_0TargetTest.cpp b/graphics/mapper/3.0/vts/functional/VtsHalGraphicsMapperV3_0TargetTest.cpp
index 430a526..b198f21 100644
--- a/graphics/mapper/3.0/vts/functional/VtsHalGraphicsMapperV3_0TargetTest.cpp
+++ b/graphics/mapper/3.0/vts/functional/VtsHalGraphicsMapperV3_0TargetTest.cpp
@@ -298,8 +298,15 @@
                                static_cast<int32_t>(info.height)};
     int fence = -1;
     uint8_t* data;
+    int32_t bytesPerPixel = -1;
+    int32_t bytesPerStride = -1;
     ASSERT_NO_FATAL_FAILURE(
-        data = static_cast<uint8_t*>(mGralloc->lock(bufferHandle, info.usage, region, fence)));
+            data = static_cast<uint8_t*>(mGralloc->lock(bufferHandle, info.usage, region, fence,
+                                                        &bytesPerPixel, &bytesPerStride)));
+
+    // Valid return values are -1 for unsupported or the number bytes for supported which is >=0
+    EXPECT_GT(bytesPerPixel, -1);
+    EXPECT_GT(bytesPerStride, -1);
 
     // RGBA_8888
     size_t strideInBytes = stride * 4;
@@ -312,9 +319,13 @@
 
     ASSERT_NO_FATAL_FAILURE(fence = mGralloc->unlock(bufferHandle));
 
+    bytesPerPixel = -1;
+    bytesPerStride = -1;
+
     // lock again for reading
     ASSERT_NO_FATAL_FAILURE(
-        data = static_cast<uint8_t*>(mGralloc->lock(bufferHandle, info.usage, region, fence)));
+            data = static_cast<uint8_t*>(mGralloc->lock(bufferHandle, info.usage, region, fence,
+                                                        &bytesPerPixel, &bytesPerStride)));
     for (uint32_t y = 0; y < info.height; y++) {
         for (size_t i = 0; i < writeInBytes; i++) {
             EXPECT_EQ(static_cast<uint8_t>(y), data[i]);
@@ -322,6 +333,9 @@
         data += strideInBytes;
     }
 
+    EXPECT_GT(bytesPerPixel, -1);
+    EXPECT_GT(bytesPerStride, -1);
+
     ASSERT_NO_FATAL_FAILURE(fence = mGralloc->unlock(bufferHandle));
     if (fence >= 0) {
         close(fence);