diff --git a/src/coreclr/vm/i386/pinvokestubs.S b/src/coreclr/vm/i386/pinvokestubs.S
index 1bdbf242cf60da..0755b507021b8f 100644
--- a/src/coreclr/vm/i386/pinvokestubs.S
+++ b/src/coreclr/vm/i386/pinvokestubs.S
@@ -12,9 +12,44 @@
 //
 //
 LEAF_ENTRY JIT_PInvokeBegin, _TEXT
-        // Not yet supported
-        int 3
+
+        // set first slot to the value of InlinedCallFrame identifier (checked by runtime code)
+        mov             dword ptr [ecx], FRAMETYPE_InlinedCallFrame
+
+        mov             dword ptr [ecx + InlinedCallFrame__m_Datum], 0
+
+        mov             eax, esp
+        add             eax, 4
+        mov             dword ptr [ecx + InlinedCallFrame__m_pCallSiteSP], eax
+        mov             dword ptr [ecx + InlinedCallFrame__m_pCalleeSavedFP], ebp
+
+        mov             eax, [esp]
+        mov             dword ptr [ecx + InlinedCallFrame__m_pCallerReturnAddress], eax
+
+        // edx = GetThread(). Trashes eax
+        push            ecx
+        push            edx
+        push            esi
+        push            edi
+        call            C_FUNC(GetThreadHelper)
+        pop             edi
+        pop             esi
+        pop             edx
+        pop             ecx
+        mov             edx, eax
+
+        // pFrame->m_Next = pThread->m_pFrame;
+        mov             eax, dword ptr [edx + Thread_m_pFrame]
+        mov             dword ptr [ecx + Frame__m_Next], eax
+
+        // pThread->m_pFrame = pFrame;
+        mov             dword ptr [edx + Thread_m_pFrame], ecx
+
+        // pThread->m_fPreemptiveGCDisabled = 0
+        mov             dword ptr [edx + Thread_m_fPreemptiveGCDisabled], 0
+
         ret
+
 LEAF_END JIT_PInvokeBegin, _TEXT
 
 //
@@ -24,9 +59,36 @@ LEAF_END JIT_PInvokeBegin, _TEXT
 //
 //
 LEAF_ENTRY JIT_PInvokeEnd, _TEXT
-        // Not yet supported
-        int 3
+
+        // edx = GetThread(). Trashes eax
+        push            ecx
+        push            edx
+        push            esi
+        push            edi
+        call            C_FUNC(GetThreadHelper)
+        pop             edi
+        pop             esi
+        pop             edx
+        pop             ecx
+        mov             edx, eax
+
+        // ecx = pFrame
+        // edx = pThread
+
+        // pThread->m_fPreemptiveGCDisabled = 1
+        mov             dword ptr [edx + Thread_m_fPreemptiveGCDisabled], 1
+
+        // Check return trap
+        PREPARE_EXTERNAL_VAR g_TrapReturningThreads, eax
+        cmp             DWORD PTR [eax], 0
+        jnz             C_FUNC(JIT_PInvokeEndRarePath)
+
+        // pThread->m_pFrame = pFrame->m_Next
+        mov             eax, dword ptr [ecx + Frame__m_Next]
+        mov             dword ptr [edx + Thread_m_pFrame], eax
+
         ret
+
 LEAF_END JIT_PInvokeEnd, _TEXT
 
 //