diff --git a/core/libs/prx/libSceRazorCpu/Export.cpp b/core/libs/prx/libSceRazorCpu/Export.cpp
index 7b418022c..23369d115 100644
--- a/core/libs/prx/libSceRazorCpu/Export.cpp
+++ b/core/libs/prx/libSceRazorCpu/Export.cpp
@@ -59,4 +59,8 @@ int APS5_VABI sceRazorCpuWriteBookmark(const char* label, const char* descriptio
  return 0;
 }
 
+int APS5_VABI sceRazorCpuSync(void) {
+ return 0;
+}
+
 }
diff --git a/core/libs/tests/GuestRazorCpu.cpp b/core/libs/tests/GuestRazorCpu.cpp
index e4af18eed..85f04438f 100644
--- a/core/libs/tests/GuestRazorCpu.cpp
+++ b/core/libs/tests/GuestRazorCpu.cpp
@@ -13,6 +13,7 @@ int APS5_VABI sceRazorCpuPopMarker(void);
 int APS5_VABI sceRazorCpuFlushOccurred(std::uint64_t* timeSpentInFlush);
 int APS5_VABI sceRazorCpuPlotValue(const char* series, float value);
 int APS5_VABI sceRazorCpuWriteBookmark(const char* label, const char* description);
+int APS5_VABI sceRazorCpuSync(void);
 }
 
 namespace {
@@ -41,4 +42,7 @@ int main() {
     Require(sceRazorCpuPlotValue("read time (ms)", 1.5f) == 0);
     Require(sceRazorCpuWriteBookmark("read timeout", "lba=0x10") == 0);
     Require(sceRazorCpuWriteBookmark("read timeout", nullptr) == 0);
+    Require(sceRazorCpuSync() == 0);
+    Require(sceRazorCpuSync() == 0);
+    Require(sceRazorCpuIsCapturing() == 0);
 }
diff --git a/docs/dev/debt/libSceRazorCpu.md b/docs/dev/debt/libSceRazorCpu.md
index 74dd2dc4f..0c42c424a 100644
--- a/docs/dev/debt/libSceRazorCpu.md
+++ b/docs/dev/debt/libSceRazorCpu.md
@@ -3,6 +3,7 @@
 ### Silent stubs
 
 - [sceRazorCpuPushMarker](../../../core/libs/prx/libSceRazorCpu/Export.cpp) (libSceRazorCpu) - signature (label, color, flags) from [SharpProspero](https://github.com/SvenGDK/SharpProspero), the same as sceRazorCpuPushMarkerStatic's except that the label is copied; it does nothing without a capture and returns 0
+- [sceRazorCpuSync](../../../core/libs/prx/libSceRazorCpu/Export.cpp) (libSceRazorCpu) - the `int(void)` signature and its meaning, an unnamed frame-boundary event, come from [SharpProspero](https://github.com/SvenGDK/SharpProspero/blob/5dfdb4b0b166e83dc9ae275001afb695f12c7174/src/SharpProspero/Interop/Debug/RazorCpu.cs#L119-L122). Without a capture there is no event to record, so it does nothing and returns 0, like the other `sceRazorCpu*` markers here and the [shadPS4](https://github.com/shadps4-emu/shadPS4/blob/3a9f57265d28975658f1ca941daa5c879c7a74bd/src/core/libraries/razor_cpu/razor_cpu.cpp#L143-L146) stub. PRAGMATA (PPSA02530) continues on 0; the console's result with no capture attached is unverified
 
 ### Unknown function info