diff --git a/dlls/setupx.dll16/setupx.dll16.spec b/dlls/setupx.dll16/setupx.dll16.spec
index 615e92fd802..34e6b6815a5 100644
--- a/dlls/setupx.dll16/setupx.dll16.spec
+++ b/dlls/setupx.dll16/setupx.dll16.spec
@@ -205,7 +205,7 @@
 409  stub     IPGETDRIVERVERSION
 410  stub     IpGetVersionString #(str str ptr word str)
 411  pascal   VcpExplain(ptr long) VcpExplain16
-412  stub     DiBuildDriverIndex #(word)
+412  pascal   DiBuildDriverIndex(word) DiBuildDriverIndex16
 413  stub     DiAddSingleInfToDrvIdx #(str word word)
 414  stub     FCEGETFLAGS
 450  stub     UiMakeDlgNonBold #(word)
diff --git a/dlls/setupx.dll16/setupx_main.c b/dlls/setupx.dll16/setupx_main.c
index adc59009bd6..db15cfe6674 100644
--- a/dlls/setupx.dll16/setupx_main.c
+++ b/dlls/setupx.dll16/setupx_main.c
@@ -628,3 +628,12 @@ RETERR16 WINAPI CtlSetLddPath16(LOGDISKID16 ldid, LPSTR szPath)
     ldd.pszPath = szPath;
     return CtlSetLdd16(&ldd);
 }
+
+/***********************************************************************
+ *		DiBuildDriverIndex  (SETUPX.412)
+ */
+RETERR16 WINAPI DiBuildDriverIndex16( WORD w1 )
+{
+    FIXME( "%x: stub\n", w1 );
+    return 0;
+}