diff --git a/dlls/usp10/usp10.c b/dlls/usp10/usp10.c
index 3a226e322e3..c1fceff1d3c 100644
--- a/dlls/usp10/usp10.c
+++ b/dlls/usp10/usp10.c
@@ -1171,3 +1171,22 @@ HRESULT WINAPI ScriptLayout(int runs, const BYTE *level, int *vistolog, int *log
     }
     return S_OK;
 }
+
+/***********************************************************************
+ *      ScriptStringValidate (USP10.@)
+ *
+ * Validate a string analysis.
+ *
+ * PARAMS
+ *  ssa [I] string analysis.
+ *
+ * RETURNS
+ *  Success: S_OK
+ *  Failure: S_FALSE if invalid sequences are found
+ *           or a non-zero HRESULT if it fails.
+ */
+HRESULT WINAPI ScriptStringValidate(SCRIPT_STRING_ANALYSIS ssa)
+{
+    FIXME("(%p): stub\n", ssa);
+    return S_OK;
+}
diff --git a/dlls/usp10/usp10.spec b/dlls/usp10/usp10.spec
index 95a6c77e5da..56fd85b5de1 100644
--- a/dlls/usp10/usp10.spec
+++ b/dlls/usp10/usp10.spec
@@ -23,7 +23,7 @@
 @ stub ScriptStringGetLogicalWidths
 @ stub ScriptStringGetOrder
 @ stdcall ScriptStringOut(ptr long long long ptr long long long)
-@ stub ScriptStringValidate
+@ stdcall ScriptStringValidate(ptr)
 @ stdcall ScriptStringXtoCP(ptr long ptr ptr)
 @ stub ScriptString_pLogAttr
 @ stub ScriptString_pSize