diff --git a/dlls/d3d11/inputlayout.c b/dlls/d3d11/inputlayout.c
index 127ea299479..de40edab7b0 100644
--- a/dlls/d3d11/inputlayout.c
+++ b/dlls/d3d11/inputlayout.c
@@ -21,6 +21,7 @@
 #include "wine/port.h"
 
 #include "d3d11_private.h"
+#include "winternl.h"
 
 WINE_DEFAULT_DEBUG_CHANNEL(d3d11);
 
@@ -32,7 +33,7 @@ static struct wined3d_shader_signature_element *shader_find_signature_element(co
 
     for (i = 0; i < s->element_count; ++i)
     {
-        if (!strcasecmp(e[i].semantic_name, semantic_name) && e[i].semantic_idx == semantic_idx
+        if (!_strnicmp(e[i].semantic_name, semantic_name, -1) && e[i].semantic_idx == semantic_idx
                 && e[i].stream_idx == stream_idx)
             return &e[i];
     }
diff --git a/dlls/d3d11/shader.c b/dlls/d3d11/shader.c
index 2276dd72ef0..a506aacfea1 100644
--- a/dlls/d3d11/shader.c
+++ b/dlls/d3d11/shader.c
@@ -21,6 +21,7 @@
 #include "wine/port.h"
 
 #include "d3d11_private.h"
+#include "winternl.h"
 
 WINE_DEFAULT_DEBUG_CHANNEL(d3d11);
 
@@ -1026,7 +1027,7 @@ static HRESULT validate_stream_output_entries(const D3D11_SO_DECLARATION_ENTRY *
                 continue;
 
             if (e1->Stream == e2->Stream
-                    && !strcasecmp(e1->SemanticName, e2->SemanticName)
+                    && !_strnicmp(e1->SemanticName, e2->SemanticName, -1)
                     && e1->SemanticIndex == e2->SemanticIndex
                     && e1->StartComponent < e2->StartComponent + e2->ComponentCount
                     && e1->StartComponent + e1->ComponentCount > e2->StartComponent)