diff --git a/server/TracyEvent.hpp b/server/TracyEvent.hpp
index 8557a785..b241a91a 100644
--- a/server/TracyEvent.hpp
+++ b/server/TracyEvent.hpp
@@ -179,7 +179,7 @@ private:
     uint8_t m_val[6];
 };
 
-struct Int48Sort { bool operator()( const Int48& lhs, const Int48& rhs ) { return lhs.Val() < rhs.Val(); }; };
+struct Int48Sort { bool operator()( const Int48& lhs, const Int48& rhs ) const { return lhs.Val() < rhs.Val(); }; };
 
 
 struct SourceLocationBase
@@ -264,7 +264,7 @@ struct SampleData
 
 enum { SampleDataSize = sizeof( SampleData ) };
 
-struct SampleDataSort { bool operator()( const SampleData& lhs, const SampleData& rhs ) { return lhs.time.Val() < rhs.time.Val(); }; };
+struct SampleDataSort { bool operator()( const SampleData& lhs, const SampleData& rhs ) const { return lhs.time.Val() < rhs.time.Val(); }; };
 
 
 struct SampleDataRange
@@ -742,7 +742,7 @@ enum class PlotValueFormatting : uint8_t
 
 struct PlotData
 {
-    struct PlotItemSort { bool operator()( const PlotItem& lhs, const PlotItem& rhs ) { return lhs.time.Val() < rhs.time.Val(); }; };
+    struct PlotItemSort { bool operator()( const PlotItem& lhs, const PlotItem& rhs ) const { return lhs.time.Val() < rhs.time.Val(); }; };
 
     uint64_t name;
     double min;
diff --git a/server/TracyWorker.hpp b/server/TracyWorker.hpp
index 75700d81..2da4010a 100644
--- a/server/TracyWorker.hpp
+++ b/server/TracyWorker.hpp
@@ -198,7 +198,7 @@ public:
 private:
     struct SourceLocationZones
     {
-        struct ZtdSort { bool operator()( const ZoneThreadData& lhs, const ZoneThreadData& rhs ) { return lhs.Zone()->Start() < rhs.Zone()->Start(); } };
+        struct ZtdSort { bool operator()( const ZoneThreadData& lhs, const ZoneThreadData& rhs ) const { return lhs.Zone()->Start() < rhs.Zone()->Start(); } };
 
         SortedVector<ZoneThreadData, ZtdSort> zones;
         int64_t min = std::numeric_limits<int64_t>::max();
@@ -217,7 +217,7 @@ private:
 
     struct GpuSourceLocationZones
     {
-        struct GpuZtdSort { bool operator()( const GpuZoneThreadData& lhs, const GpuZoneThreadData& rhs ) { return lhs.Zone()->GpuStart() < rhs.Zone()->GpuStart(); } };
+        struct GpuZtdSort { bool operator()( const GpuZoneThreadData& lhs, const GpuZoneThreadData& rhs ) const { return lhs.Zone()->GpuStart() < rhs.Zone()->GpuStart(); } };
 
         SortedVector<GpuZoneThreadData, GpuZtdSort> zones;
         int64_t min = std::numeric_limits<int64_t>::max();