diff --git a/dynhooks_sourcepawn.cpp b/dynhooks_sourcepawn.cpp
index 03a885c..1d9158a 100644
--- a/dynhooks_sourcepawn.cpp
+++ b/dynhooks_sourcepawn.cpp
@@ -252,6 +252,10 @@ bool UpdateRegisterArgumentSizes(CHook* pDetour, HookSetup *setup)
 // Central handler for all detours. Heart of the detour support.
 ReturnAction_t HandleDetour(HookType_t hookType, CHook* pDetour)
 {
+	// Can't call into SourcePawn offthread.
+	if (g_MainThreadId != ke::GetCurrentThreadId())
+		return ReturnAction_Ignored;
+
 	DetourMap *map;
 	if (hookType == HOOKTYPE_PRE)
 		map = &g_pPreDetours;
diff --git a/extension.cpp b/extension.cpp
index 0e905b3..c7e3105 100644
--- a/extension.cpp
+++ b/extension.cpp
@@ -15,6 +15,8 @@ HandleType_t g_HookSetupHandle = 0;
 HandleType_t g_HookParamsHandle = 0;
 HandleType_t g_HookReturnHandle = 0;
 
+ke::ThreadId g_MainThreadId;
+
 bool DHooks::SDK_OnLoad(char *error, size_t maxlength, bool late)
 {
 	HandleError err;
@@ -59,6 +61,7 @@ bool DHooks::SDK_OnLoad(char *error, size_t maxlength, bool late)
 
 	g_pEntityListener = new DHooksEntityListener();
 	g_pSignatures = new SignatureGameConfig();
+	g_MainThreadId = ke::GetCurrentThreadId();
 
 	return true;
 }
diff --git a/extension.h b/extension.h
index c6e7045..f66276a 100644
--- a/extension.h
+++ b/extension.h
@@ -43,6 +43,7 @@
 #include <IBinTools.h>
 #include <ISDKTools.h>
 #include "sdk-hacks.h"
+#include <amtl/am-thread-utils.h>
 
 /**
  * @brief Sample implementation of the SDK Extension.
@@ -129,4 +130,5 @@ public:
 };
 extern SourceHook::IHookManagerAutoGen *g_pHookManager;
 extern sp_nativeinfo_t g_Natives[];
+extern ke::ThreadId g_MainThreadId;
 #endif // _INCLUDE_SOURCEMOD_EXTENSION_PROPER_H_