diff --git a/vulkano/src/command_buffer/auto/mod.rs b/vulkano/src/command_buffer/auto/mod.rs
index f8ef5e20..cbd6b93d 100644
--- a/vulkano/src/command_buffer/auto/mod.rs
+++ b/vulkano/src/command_buffer/auto/mod.rs
@@ -171,6 +171,12 @@ impl Debug for SecondaryAutoCommandBuffer {
 }
 
 impl SecondaryAutoCommandBuffer {
+    /// Returns the inner raw command buffer.
+    #[inline]
+    pub fn inner(&self) -> &RawCommandBuffer {
+        &self.inner
+    }
+
     /// Returns the usage of this command buffer.
     #[inline]
     pub fn usage(&self) -> CommandBufferUsage {
diff --git a/vulkano/src/command_buffer/commands/secondary.rs b/vulkano/src/command_buffer/commands/secondary.rs
index e7a247d1..786f8d41 100644
--- a/vulkano/src/command_buffer/commands/secondary.rs
+++ b/vulkano/src/command_buffer/commands/secondary.rs
@@ -1,7 +1,7 @@
 use crate::{
     command_buffer::{
         auto::{RenderPassStateType, Resource, ResourceUseRef2},
-        sys::RawRecordingCommandBuffer,
+        sys::{RawCommandBuffer, RawRecordingCommandBuffer},
         CommandBufferInheritanceRenderPassType, CommandBufferLevel, RecordingCommandBuffer,
         ResourceInCommand, SecondaryAutoCommandBuffer, SecondaryCommandBufferBufferUsage,
         SecondaryCommandBufferImageUsage, SecondaryCommandBufferResourcesUsage, SubpassContents,
@@ -11,7 +11,7 @@ use crate::{
     Requires, RequiresAllOf, RequiresOneOf, SafeDeref, ValidationError, VulkanObject,
 };
 use smallvec::{smallvec, SmallVec};
-use std::{cmp::min, iter, ops::Deref, sync::Arc};
+use std::{cmp::min, iter, sync::Arc};
 
 /// # Commands to execute a secondary command buffer inside a primary command buffer.
 ///
@@ -58,7 +58,7 @@ impl<L> RecordingCommandBuffer<L> {
         command_buffers: impl Iterator<Item = &'a SecondaryAutoCommandBuffer> + Clone,
     ) -> Result<(), Box<ValidationError>> {
         self.inner
-            .validate_execute_commands(command_buffers.clone())?;
+            .validate_execute_commands(command_buffers.clone().map(|cb| cb.inner()))?;
 
         if let Some(render_pass_state) = &self.builder_state.render_pass {
             if render_pass_state.contents != SubpassContents::SecondaryCommandBuffers {
@@ -552,16 +552,16 @@ impl RawRecordingCommandBuffer {
     #[inline]
     pub unsafe fn execute_commands(
         &mut self,
-        command_buffers: &[Arc<SecondaryAutoCommandBuffer>],
+        command_buffers: &[&RawCommandBuffer],
     ) -> Result<&mut Self, Box<ValidationError>> {
-        self.validate_execute_commands(command_buffers.iter().map(Deref::deref))?;
+        self.validate_execute_commands(command_buffers.iter().copied())?;
 
         Ok(self.execute_commands_unchecked(command_buffers))
     }
 
     fn validate_execute_commands<'a>(
         &self,
-        command_buffers: impl Iterator<Item = &'a SecondaryAutoCommandBuffer>,
+        command_buffers: impl Iterator<Item = &'a RawCommandBuffer>,
     ) -> Result<(), Box<ValidationError>> {
         if self.level() != CommandBufferLevel::Primary {
             return Err(Box::new(ValidationError {
@@ -585,10 +585,19 @@ impl RawRecordingCommandBuffer {
             }));
         }
 
-        for (_command_buffer_index, command_buffer) in command_buffers.enumerate() {
+        for (command_buffer_index, command_buffer) in command_buffers.enumerate() {
             // VUID-vkCmdExecuteCommands-commonparent
             assert_eq!(self.device(), command_buffer.device());
 
+            if command_buffer.level() != CommandBufferLevel::Secondary {
+                return Err(Box::new(ValidationError {
+                    context: format!("command_buffers[{}]", command_buffer_index).into(),
+                    problem: "is not a secondary command buffer".into(),
+                    vuids: &["VUID-vkCmdExecuteCommands-pCommandBuffers-00088"],
+                    ..Default::default()
+                }));
+            }
+
             // TODO:
             // VUID-vkCmdExecuteCommands-pCommandBuffers-00094
         }
@@ -599,9 +608,8 @@ impl RawRecordingCommandBuffer {
         // VUID-vkCmdExecuteCommands-pCommandBuffers-00093
         // VUID-vkCmdExecuteCommands-pCommandBuffers-00105
 
-        // VUID-vkCmdExecuteCommands-pCommandBuffers-00088
         // VUID-vkCmdExecuteCommands-pCommandBuffers-00089
-        // Ensured by the SecondaryCommandBuffer trait.
+        // Partially ensured by the `RawCommandBuffer` type.
 
         Ok(())
     }
@@ -609,7 +617,7 @@ impl RawRecordingCommandBuffer {
     #[cfg_attr(not(feature = "document_unchecked"), doc(hidden))]
     pub unsafe fn execute_commands_unchecked(
         &mut self,
-        command_buffers: &[Arc<SecondaryAutoCommandBuffer>],
+        command_buffers: &[&RawCommandBuffer],
     ) -> &mut Self {
         if command_buffers.is_empty() {
             return self;