diff --git a/renderdoc/driver/vulkan/vk_common.cpp b/renderdoc/driver/vulkan/vk_common.cpp
index e124541c9..a0acc4cde 100644
--- a/renderdoc/driver/vulkan/vk_common.cpp
+++ b/renderdoc/driver/vulkan/vk_common.cpp
@@ -1149,6 +1149,8 @@ void DescriptorSetSlot::AccumulateBindRefs(DescriptorBindRefs &refs, VulkanResou
   RDCCOMPILE_ASSERT(uint64_t(DescriptorSlotType::Count) <= 0xff,
                     "DescriptorSlotType is no longer 8-bit");
   RDCCOMPILE_ASSERT(sizeof(DescriptorSetSlot) == 32, "DescriptorSetSlot is no longer 32 bytes");
+  RDCCOMPILE_ASSERT(offsetof(DescriptorSetSlot, offset) == 8,
+                    "DescriptorSetSlot first uint64_t bitpacking isn't working as expected");
 
   VkResourceRecord *bufView = NULL, *imgView = NULL, *buffer = NULL;
 
diff --git a/renderdoc/driver/vulkan/vk_common.h b/renderdoc/driver/vulkan/vk_common.h
index 78e063b19..098da720f 100644
--- a/renderdoc/driver/vulkan/vk_common.h
+++ b/renderdoc/driver/vulkan/vk_common.h
@@ -460,8 +460,24 @@ struct MemoryAllocation
 struct VkResourceRecord;
 class VulkanResourceManager;
 
+// gcc is buggy garbage, and if these enums are compiled as uint64_t it will warn (until gcc 9) that
+// the enum won't fit in an 8-bit bitfield.
+// As a workaround we use pragma push to pack an explicit uint8_t into a uint64_t:48
+
+#if defined(__GNUC__) && (__GNUC__ < 10)
+
+#define EnumBaseType uint8_t
+#define GCC_WORKAROUND 1
+
+#else
+
+#define EnumBaseType uint64_t
+#define GCC_WORKAROUND 0
+
+#endif
+
 // we inherit from uint64_t to make this more bitfield-able but we intend for this to fit in uint8_t
-enum class DescriptorSlotType : uint64_t
+enum class DescriptorSlotType : EnumBaseType
 {
   // we want an unwritten type as 0 so that zero-initialised descriptors that haven't been written
   // don't look like samplers, so these unfortunately don't match VkDescriptorType in value.
@@ -526,8 +542,7 @@ constexpr DescriptorSlotType convert(VkDescriptorType type)
   // clang-format on
 }
 
-// we inherit from uint64_t to make this more bitfield-able but we intend for this to fit in uint8_t
-enum class DescriptorSlotImageLayout : uint64_t
+enum class DescriptorSlotImageLayout : EnumBaseType
 {
   // these match the core types
   Undefined = 0,
@@ -637,6 +652,10 @@ struct DescriptorSetSlot
   // 48-bit truncated VK_WHOLE_SIZE
   static const VkDeviceSize WholeSizeRange = 0xFFFFFFFFFFFF;
   VkDeviceSize GetRange() const { return range == WholeSizeRange ? VK_WHOLE_SIZE : range; }
+#if GCC_WORKAROUND
+#pragma pack(push, 1)
+#endif
+
   // used for buffers, we assume the max buffer size is less than 1<<48.
   // this is placed first to allow writes to just mask the top bits on read or write and remain
   // aligned, then the type/layout below can be accessed directly as bytes.
@@ -648,6 +667,10 @@ struct DescriptorSetSlot
   // used for images, the image layout
   DescriptorSlotImageLayout imageLayout : 8;
 
+#if GCC_WORKAROUND
+#pragma pack(pop)
+#endif
+
   // used for buffers and inline blocks. We could steal some bits here if we needed them since 48
   // bits would be plenty for a long time.
   VkDeviceSize offset;