diff --git a/TracyOpenGL.hpp b/TracyOpenGL.hpp
index 8df50ba6..58b17ba0 100644
--- a/TracyOpenGL.hpp
+++ b/TracyOpenGL.hpp
@@ -15,6 +15,7 @@
 #else
 
 #include <atomic>
+#include <assert.h>
 #include <stdlib.h>
 
 #include "Tracy.hpp"
@@ -39,7 +40,7 @@
 namespace tracy
 {
 
-extern std::atomic<uint16_t> s_gpuCtxCounter;
+extern std::atomic<uint8_t> s_gpuCtxCounter;
 
 class GpuCtx
 {
@@ -53,6 +54,8 @@ public:
         , m_head( 0 )
         , m_tail( 0 )
     {
+        assert( m_context != 255 );
+
         glGenQueries( QueryCount, m_query );
 
         int64_t tgpu;
@@ -142,13 +145,13 @@ private:
         return m_query[id];
     }
 
-    tracy_force_inline uint16_t GetId() const
+    tracy_force_inline uint8_t GetId() const
     {
         return m_context;
     }
 
     unsigned int m_query[QueryCount];
-    uint16_t m_context;
+    uint8_t m_context;
 
     unsigned int m_head;
     unsigned int m_tail;
diff --git a/TracyVulkan.hpp b/TracyVulkan.hpp
index e307ee3f..8ea81237 100644
--- a/TracyVulkan.hpp
+++ b/TracyVulkan.hpp
@@ -13,6 +13,7 @@
 
 #else
 
+#include <assert.h>
 #include <stdlib.h>
 #include <vulkan/vulkan.h>
 #include "Tracy.hpp"
@@ -36,7 +37,7 @@
 namespace tracy
 {
 
-extern std::atomic<uint16_t> s_gpuCtxCounter;
+extern std::atomic<uint8_t> s_gpuCtxCounter;
 
 class VkCtx
 {
@@ -53,6 +54,8 @@ public:
         , m_tail( 0 )
         , m_oldCnt( 0 )
     {
+        assert( m_context != 255 );
+
         VkPhysicalDeviceProperties prop;
         vkGetPhysicalDeviceProperties( physdev, &prop );
         const float period = prop.limits.timestampPeriod;
@@ -167,7 +170,7 @@ private:
         return id;
     }
 
-    tracy_force_inline uint16_t GetId() const
+    tracy_force_inline uint8_t GetId() const
     {
         return m_context;
     }
@@ -175,7 +178,7 @@ private:
     VkDevice m_device;
     VkQueue m_queue;
     VkQueryPool m_query;
-    uint16_t m_context;
+    uint8_t m_context;
 
     unsigned int m_head;
     unsigned int m_tail;
diff --git a/client/TracyProfiler.cpp b/client/TracyProfiler.cpp
index bc64b886..f1c4fd8d 100644
--- a/client/TracyProfiler.cpp
+++ b/client/TracyProfiler.cpp
@@ -169,7 +169,7 @@ static InitTimeWrapper init_order(101) s_initTime { SetupHwTimer() };
 static RPMallocInit init_order(102) s_rpmalloc_init;
 moodycamel::ConcurrentQueue<QueueItem> init_order(103) s_queue( QueuePrealloc );
 std::atomic<uint32_t> init_order(104) s_lockCounter( 0 );
-std::atomic<uint16_t> init_order(104) s_gpuCtxCounter( 0 );
+std::atomic<uint8_t> init_order(104) s_gpuCtxCounter( 0 );
 
 thread_local GpuCtxWrapper init_order(104) s_gpuCtx { nullptr };
 VkCtxWrapper init_order(104) s_vkCtx { nullptr };
diff --git a/common/TracyQueue.hpp b/common/TracyQueue.hpp
index 54889766..52b7f2b9 100644
--- a/common/TracyQueue.hpp
+++ b/common/TracyQueue.hpp
@@ -168,7 +168,7 @@ struct QueueGpuNewContext
     int64_t gpuTime;
     uint64_t thread;
     float period;
-    uint16_t context;
+    uint8_t context;
     uint8_t accuracyBits;
 };
 
@@ -177,26 +177,26 @@ struct QueueGpuZoneBegin
     int64_t cpuTime;
     uint64_t srcloc;
     uint64_t thread;
-    uint16_t context;
+    uint8_t context;
 };
 
 struct QueueGpuZoneEnd
 {
     int64_t cpuTime;
-    uint16_t context;
+    uint8_t context;
 };
 
 struct QueueGpuTime
 {
     int64_t gpuTime;
-    uint16_t context;
+    uint8_t context;
 };
 
 struct QueueGpuResync
 {
     int64_t cpuTime;
     int64_t gpuTime;
-    uint16_t context;
+    uint8_t context;
 };
 
 struct QueueMemAlloc
diff --git a/server/TracyWorker.hpp b/server/TracyWorker.hpp
index 368b2e70..37bf188c 100644
--- a/server/TracyWorker.hpp
+++ b/server/TracyWorker.hpp
@@ -322,7 +322,7 @@ private:
     char* m_buffer;
     int m_bufferOffset;
 
-    flat_hash_map<uint16_t, GpuCtxData*, nohash<uint16_t>> m_gpuCtxMap;
+    flat_hash_map<uint8_t, GpuCtxData*, nohash<uint8_t>> m_gpuCtxMap;
     flat_hash_map<uint64_t, StringLocation, nohash<uint64_t>> m_pendingCustomStrings;
     flat_hash_map<uint64_t, PlotData*, nohash<uint64_t>> m_pendingPlots;
     flat_hash_map<uint64_t, uint32_t> m_pendingCallstacks;