diff --git a/apps/system_monitor.cpp b/apps/system_monitor.cpp
index 6990705..5fb1501 100644
--- a/apps/system_monitor.cpp
+++ b/apps/system_monitor.cpp
@@ -237,14 +237,14 @@ void UpdateDisplay(Instance *instance, int index) {
 		EsPanelSwitchTo(instance->switcher, instance->listViewProcesses, ES_TRANSITION_NONE);
 		EsElementFocus(instance->listViewProcesses);
 	} else if (index == DISPLAY_GENERAL_LOG) {
-		size_t bytes = EsSyscall(ES_SYSCALL_DEBUG_COMMAND, index, (uintptr_t) generalLogBuffer, sizeof(generalLogBuffer), 0);
+		size_t bytes = _EsDebugCommand(index, (uintptr_t) generalLogBuffer, sizeof(generalLogBuffer), 0);
 		EsTextboxSelectAll(instance->textboxGeneralLog);
 		EsTextboxInsert(instance->textboxGeneralLog, generalLogBuffer, bytes);
 		EsTextboxEnsureCaretVisible(instance->textboxGeneralLog, false);
 		EsPanelSwitchTo(instance->switcher, instance->textboxGeneralLog, ES_TRANSITION_NONE);
 	} else if (index == DISPLAY_MEMORY) {
 		EsMemoryStatistics statistics = {};
-		EsSyscall(ES_SYSCALL_DEBUG_COMMAND, index, (uintptr_t) &statistics, 0, 0);
+		_EsDebugCommand(index, (uintptr_t) &statistics, 0, 0);
 
 		EsPanelSwitchTo(instance->switcher, instance->panelMemoryStatistics, ES_TRANSITION_NONE);
 
diff --git a/desktop/os.header b/desktop/os.header
index 29eddb7..f99b0ac 100644
--- a/desktop/os.header
+++ b/desktop/os.header
@@ -763,7 +763,7 @@ enum EsFatalError {
 	ES_FATAL_ERROR_COUNT
 }
 
-enum EsSyscallType {
+private enum EsSyscallType {
 	// Memory.
 
 	ES_SYSCALL_MEMORY_ALLOCATE
@@ -1179,7 +1179,7 @@ struct EsElementPublic {
 	uint64_t flags; // Bits 0-31: specific to the type of element; bits 32-63: common to all elements.
 };
 
-struct EsBatchCall {
+private struct EsBatchCall {
 	EsSyscallType index; 
 	bool stopBatchIfError;
 	union { uintptr_t argument0, returnValue; };
@@ -1241,7 +1241,7 @@ struct EsMutex {
 
 struct EsCrashReason {
 	EsFatalError errorCode;
-	EsSyscallType duringSystemCall;
+	int32_t duringSystemCall;
 }
 
 struct EsProcessState {
@@ -1949,8 +1949,9 @@ function void EsPOSIXInitialise(int *argc, char ***argv);
 function intptr_t EsPOSIXSystemCall(intptr_t n, intptr_t a1, intptr_t a2, intptr_t a3, intptr_t a4, intptr_t a5, intptr_t a6); 
 function char *EsPOSIXConvertPath(const char *path, size_t *outNameLength, bool addPOSIXMountPointPrefix);
 
-function void EsBatch(EsBatchCall *calls, size_t count); 
-function uintptr_t _EsSyscall(uintptr_t a, uintptr_t b, uintptr_t c, uintptr_t d, uintptr_t e, uintptr_t f); 
+private function void EsBatch(EsBatchCall *calls, size_t count); 
+private function uintptr_t _EsSyscall(uintptr_t a, uintptr_t b, uintptr_t c, uintptr_t d, uintptr_t e, uintptr_t f); 
+function uintptr_t _EsDebugCommand(uintptr_t a, uintptr_t b, uintptr_t c, uintptr_t d);
 
 // Configuration and settings.
 
diff --git a/desktop/syscall.cpp b/desktop/syscall.cpp
index 6bade1b..fa338d8 100644
--- a/desktop/syscall.cpp
+++ b/desktop/syscall.cpp
@@ -911,3 +911,7 @@ size_t EsPipeWrite(EsHandle pipe, const void *buffer, size_t bytes) {
 EsError EsDeviceControl(EsHandle handle, EsDeviceControlType type, void *dp, void *dq) {
 	return EsSyscall(ES_SYSCALL_DEVICE_CONTROL, handle, type, (uintptr_t) dp, (uintptr_t) dq);
 }
+
+uintptr_t _EsDebugCommand(uintptr_t a, uintptr_t b, uintptr_t c, uintptr_t d) {
+	return EsSyscall(ES_SYSCALL_DEBUG_COMMAND, a, b, c, d);
+}
diff --git a/util/api_table.ini b/util/api_table.ini
index c970b08..2eca7c4 100644
--- a/util/api_table.ini
+++ b/util/api_table.ini
@@ -489,3 +489,4 @@ EsScrollViewIsBarEnabled=487
 EsScrollViewIsInDragScroll=488
 _EsOpenDocumentEnumerate=489
 EsDialogGetContentArea=490
+_EsDebugCommand=491