diff --git a/dlls/imm32/imm.c b/dlls/imm32/imm.c
index f0850802bc1..6f9744872b6 100644
--- a/dlls/imm32/imm.c
+++ b/dlls/imm32/imm.c
@@ -2130,6 +2130,13 @@ BOOL WINAPI ImmSetCompositionStringA(
     if (!data)
         return FALSE;
 
+    if (!(dwIndex == SCS_SETSTR ||
+          dwIndex == SCS_CHANGEATTR ||
+          dwIndex == SCS_CHANGECLAUSE ||
+          dwIndex == SCS_SETRECONVERTSTRING ||
+          dwIndex == SCS_QUERYRECONVERTSTRING))
+        return FALSE;
+
     if (!is_himc_ime_unicode(data))
         return data->immKbd->pImeSetCompositionString(hIMC, dwIndex, lpComp,
                         dwCompLen, lpRead, dwReadLen);
@@ -2178,6 +2185,13 @@ BOOL WINAPI ImmSetCompositionStringW(
     if (!data)
         return FALSE;
 
+    if (!(dwIndex == SCS_SETSTR ||
+          dwIndex == SCS_CHANGEATTR ||
+          dwIndex == SCS_CHANGECLAUSE ||
+          dwIndex == SCS_SETRECONVERTSTRING ||
+          dwIndex == SCS_QUERYRECONVERTSTRING))
+        return FALSE;
+
     if (is_himc_ime_unicode(data))
         return data->immKbd->pImeSetCompositionString(hIMC, dwIndex, lpComp,
                         dwCompLen, lpRead, dwReadLen);
diff --git a/dlls/imm32/tests/imm32.c b/dlls/imm32/tests/imm32.c
index 97a72014b92..7b76226eb11 100644
--- a/dlls/imm32/tests/imm32.c
+++ b/dlls/imm32/tests/imm32.c
@@ -274,22 +274,18 @@ static void test_ImmSetCompositionString(void)
 
     ret = ImmSetCompositionStringW(imc, SCS_SETSTR | SCS_CHANGEATTR,
         NULL, 0, NULL, 0);
-    todo_wine
     ok(!ret, "ImmSetCompositionStringW() succeeded.\n");
 
     ret = ImmSetCompositionStringW(imc, SCS_SETSTR | SCS_CHANGECLAUSE,
         NULL, 0, NULL, 0);
-    todo_wine
     ok(!ret, "ImmSetCompositionStringW() succeeded.\n");
 
     ret = ImmSetCompositionStringW(imc, SCS_CHANGEATTR | SCS_CHANGECLAUSE,
         NULL, 0, NULL, 0);
-    todo_wine
     ok(!ret, "ImmSetCompositionStringW() succeeded.\n");
 
     ret = ImmSetCompositionStringW(imc, SCS_SETSTR | SCS_CHANGEATTR | SCS_CHANGECLAUSE,
         NULL, 0, NULL, 0);
-    todo_wine
     ok(!ret, "ImmSetCompositionStringW() succeeded.\n");
 
     ImmReleaseContext(hwnd, imc);