diff --git a/dlls/imm32/imm.c b/dlls/imm32/imm.c
index 481f98f72de..3f5ad314e73 100644
--- a/dlls/imm32/imm.c
+++ b/dlls/imm32/imm.c
@@ -2249,6 +2249,9 @@ BOOL WINAPI ImmSetCandidateWindow(
     if (!data || !lpCandidate)
         return FALSE;
 
+    if (IMM_IsCrossThreadAccess(NULL, hIMC))
+        return FALSE;
+
     TRACE("\t%x, %x, (%i,%i), (%i,%i - %i,%i)\n",
             lpCandidate->dwIndex, lpCandidate->dwStyle,
             lpCandidate->ptCurrentPos.x, lpCandidate->ptCurrentPos.y,
@@ -2279,6 +2282,9 @@ BOOL WINAPI ImmSetCompositionFontA(HIMC hIMC, LPLOGFONTA lplf)
         return FALSE;
     }
 
+    if (IMM_IsCrossThreadAccess(NULL, hIMC))
+        return FALSE;
+
     memcpy(&data->IMC.lfFont.W,lplf,sizeof(LOGFONTA));
     MultiByteToWideChar(CP_ACP, 0, lplf->lfFaceName, -1, data->IMC.lfFont.W.lfFaceName,
                         LF_FACESIZE);
@@ -2302,6 +2308,9 @@ BOOL WINAPI ImmSetCompositionFontW(HIMC hIMC, LPLOGFONTW lplf)
         return FALSE;
     }
 
+    if (IMM_IsCrossThreadAccess(NULL, hIMC))
+        return FALSE;
+
     data->IMC.lfFont.W = *lplf;
     ImmNotifyIME(hIMC, NI_CONTEXTUPDATED, 0, IMC_SETCOMPOSITIONFONT);
     ImmInternalSendIMENotify(data, IMN_SETCOMPOSITIONFONT, 0);
@@ -2443,6 +2452,9 @@ BOOL WINAPI ImmSetCompositionWindow(
         return FALSE;
     }
 
+    if (IMM_IsCrossThreadAccess(NULL, hIMC))
+        return FALSE;
+
     data->IMC.cfCompForm = *lpCompForm;
 
     if (IsWindowVisible(data->immKbd->UIWnd))
@@ -2477,6 +2489,9 @@ BOOL WINAPI ImmSetConversionStatus(
         return FALSE;
     }
 
+    if (IMM_IsCrossThreadAccess(NULL, hIMC))
+        return FALSE;
+
     if ( fdwConversion != data->IMC.fdwConversion )
     {
         oldConversion = data->IMC.fdwConversion;
@@ -2510,6 +2525,9 @@ BOOL WINAPI ImmSetOpenStatus(HIMC hIMC, BOOL fOpen)
         return FALSE;
     }
 
+    if (IMM_IsCrossThreadAccess(NULL, hIMC))
+        return FALSE;
+
     if (data->immKbd->UIWnd == NULL)
     {
         /* create the ime window */
@@ -2546,6 +2564,9 @@ BOOL WINAPI ImmSetStatusWindowPos(HIMC hIMC, LPPOINT lpptPos)
         return FALSE;
     }
 
+    if (IMM_IsCrossThreadAccess(NULL, hIMC))
+        return FALSE;
+
     TRACE("\t(%i,%i)\n", lpptPos->x, lpptPos->y);
 
     data->IMC.ptStatusWndPos = *lpptPos;
diff --git a/dlls/imm32/tests/imm32.c b/dlls/imm32/tests/imm32.c
index d7854c68696..870f5d23527 100644
--- a/dlls/imm32/tests/imm32.c
+++ b/dlls/imm32/tests/imm32.c
@@ -525,15 +525,15 @@ static void test_ImmThreads(void)
     ok(rc == 0, "ImmGetOpenStatus failed\n");
 
     rc = ImmSetOpenStatus(otherHimc, TRUE);
-    todo_wine ok(rc == 0, "ImmSetOpenStatus should fail\n");
+    ok(rc == 0, "ImmSetOpenStatus should fail\n");
     rc = ImmSetOpenStatus(threadinfo.u_himc, TRUE);
-    todo_wine ok(rc == 0, "ImmSetOpenStatus should fail\n");
+    ok(rc == 0, "ImmSetOpenStatus should fail\n");
     rc = ImmGetOpenStatus(otherHimc);
-    todo_wine ok(rc == 0, "ImmGetOpenStatus failed\n");
+    ok(rc == 0, "ImmGetOpenStatus failed\n");
     rc = ImmGetOpenStatus(threadinfo.u_himc);
     ok (rc == 1 || broken(rc == 0), "ImmGetOpenStatus should return 1\n");
     rc = ImmSetOpenStatus(otherHimc, FALSE);
-    todo_wine ok(rc == 0, "ImmSetOpenStatus should fail\n");
+    ok(rc == 0, "ImmSetOpenStatus should fail\n");
     rc = ImmGetOpenStatus(otherHimc);
     ok(rc == 0, "ImmGetOpenStatus failed\n");
 
@@ -548,9 +548,9 @@ static void test_ImmThreads(void)
     rc = ImmGetCompositionFontA(threadinfo.u_himc, &lf);
     ok(rc != 0 || broken(rc == 0), "ImmGetCompositionFont user himc failed\n");
     rc = ImmSetCompositionFontA(otherHimc, &lf);
-    todo_wine ok(rc == 0, "ImmSetCompositionFont should fail\n");
+    ok(rc == 0, "ImmSetCompositionFont should fail\n");
     rc = ImmSetCompositionFontA(threadinfo.u_himc, &lf);
-    todo_wine ok(rc == 0, "ImmSetCompositionFont should fail\n");
+    ok(rc == 0, "ImmSetCompositionFont should fail\n");
 
     /* CompositionWindow */
     rc = ImmSetCompositionWindow(himc, &cf);
@@ -559,9 +559,9 @@ static void test_ImmThreads(void)
     ok(rc != 0, "ImmGetCompositionWindow failed\n");
 
     rc = ImmSetCompositionWindow(otherHimc, &cf);
-    todo_wine ok(rc == 0, "ImmSetCompositionWindow should fail\n");
+    ok(rc == 0, "ImmSetCompositionWindow should fail\n");
     rc = ImmSetCompositionWindow(threadinfo.u_himc, &cf);
-    todo_wine ok(rc == 0, "ImmSetCompositionWindow should fail\n");
+    ok(rc == 0, "ImmSetCompositionWindow should fail\n");
     rc = ImmGetCompositionWindow(otherHimc, &cf);
     ok(rc != 0 || broken(rc == 0), "ImmGetCompositionWindow failed\n");
     rc = ImmGetCompositionWindow(threadinfo.u_himc, &cf);
@@ -578,9 +578,9 @@ static void test_ImmThreads(void)
     rc = ImmGetConversionStatus(threadinfo.u_himc, &status, &sentence);
     ok(rc != 0 || broken(rc == 0), "ImmGetConversionStatus failed\n");
     rc = ImmSetConversionStatus(otherHimc, status, sentence);
-    todo_wine ok(rc == 0, "ImmSetConversionStatus should fail\n");
+    ok(rc == 0, "ImmSetConversionStatus should fail\n");
     rc = ImmSetConversionStatus(threadinfo.u_himc, status, sentence);
-    todo_wine ok(rc == 0, "ImmSetConversionStatus should fail\n");
+    ok(rc == 0, "ImmSetConversionStatus should fail\n");
 
     /* StatusWindowPos */
     rc = ImmSetStatusWindowPos(himc, &pt);
@@ -589,9 +589,9 @@ static void test_ImmThreads(void)
     ok(rc != 0, "ImmGetStatusWindowPos failed\n");
 
     rc = ImmSetStatusWindowPos(otherHimc, &pt);
-    todo_wine ok(rc == 0, "ImmSetStatusWindowPos should fail\n");
+    ok(rc == 0, "ImmSetStatusWindowPos should fail\n");
     rc = ImmSetStatusWindowPos(threadinfo.u_himc, &pt);
-    todo_wine ok(rc == 0, "ImmSetStatusWindowPos should fail\n");
+    ok(rc == 0, "ImmSetStatusWindowPos should fail\n");
     rc = ImmGetStatusWindowPos(otherHimc, &pt);
     ok(rc != 0 || broken(rc == 0), "ImmGetStatusWindowPos failed\n");
     rc = ImmGetStatusWindowPos(threadinfo.u_himc, &pt);
@@ -624,11 +624,11 @@ static void test_ImmThreads(void)
     rc = ImmGetCandidateWindow(otherHimc, 0, &cdf);
     ok (rc == 0, "ImmGetCandidateWindow should fail\n");
     rc = ImmSetCandidateWindow(otherHimc, &cdf);
-    todo_wine ok (rc == 0, "ImmSetCandidateWindow should fail\n");
+    ok (rc == 0, "ImmSetCandidateWindow should fail\n");
     rc = ImmGetCandidateWindow(threadinfo.u_himc, 0, &cdf);
     ok (rc == 1 || broken( rc == 0), "ImmGetCandidateWindow should succeed\n");
     rc = ImmSetCandidateWindow(threadinfo.u_himc, &cdf);
-    todo_wine ok (rc == 0, "ImmSetCandidateWindow should fail\n");
+    ok (rc == 0, "ImmSetCandidateWindow should fail\n");
 
     ImmReleaseContext(threadinfo.hwnd,otherHimc);
     ImmReleaseContext(hwnd,himc);