diff --git a/dlls/wined3d/glsl_shader.c b/dlls/wined3d/glsl_shader.c
index 6dfa706fb67..6f2f10a56db 100644
--- a/dlls/wined3d/glsl_shader.c
+++ b/dlls/wined3d/glsl_shader.c
@@ -1605,8 +1605,17 @@ void pshader_glsl_tex(SHADER_OPCODE_ARG* arg) {
     } else {
         glsl_src_param_t coord_param;
         shader_glsl_add_src_param(arg, arg->src[0], arg->src_addr[0], mask, &coord_param);
-        shader_addline(arg->buffer, "%s(Psampler%u, %s)%s);\n",
-                sample_function.name, sampler_idx, coord_param.param_str, dst_swizzle);
+        if(arg->opcode_token & WINED3DSI_TEXLD_BIAS) {
+            glsl_src_param_t bias;
+            shader_glsl_add_src_param(arg, arg->src[0], arg->src_addr[0], WINED3DSP_WRITEMASK_3, &bias);
+
+            shader_addline(arg->buffer, "%s(Psampler%u, %s, %s)%s);\n",
+                    sample_function.name, sampler_idx, coord_param.param_str,
+                    bias.param_str, dst_swizzle);
+        } else {
+            shader_addline(arg->buffer, "%s(Psampler%u, %s)%s);\n",
+                    sample_function.name, sampler_idx, coord_param.param_str, dst_swizzle);
+        }
     }
 }
 
diff --git a/dlls/wined3d/wined3d_private_types.h b/dlls/wined3d/wined3d_private_types.h
index 3550910101e..8a7750f8ecd 100644
--- a/dlls/wined3d/wined3d_private_types.h
+++ b/dlls/wined3d/wined3d_private_types.h
@@ -293,6 +293,7 @@ typedef enum _WINED3DSHADER_INSTRUCTION_OPCODE_TYPE {
 
 /* Undocumented opcode control to identify projective texture lookups in ps 2.0 and later */
 #define WINED3DSI_TEXLD_PROJECT 0x00010000
+#define WINED3DSI_TEXLD_BIAS    0x00020000
 
 /** Shader version tokens, and shader end tokens **/