diff --git a/dlls/wined3d/adapter_gl.c b/dlls/wined3d/adapter_gl.c
index 56aa9b73269..c2803379347 100644
--- a/dlls/wined3d/adapter_gl.c
+++ b/dlls/wined3d/adapter_gl.c
@@ -4928,6 +4928,7 @@ static void wined3d_adapter_gl_init_d3d_info(struct wined3d_adapter_gl *adapter_
     d3d_info->feature_level = feature_level_from_caps(gl_info, &shader_caps, &d3d_info->ffp_fragment_caps);
     d3d_info->filling_convention_offset = gl_info->filling_convention_offset;
     d3d_info->persistent_map = !!gl_info->supported[ARB_BUFFER_STORAGE];
+    d3d_info->ffp_hlsl = wined3d_settings.ffp_hlsl;
 
     if (gl_info->supported[ARB_TEXTURE_MULTISAMPLE])
         d3d_info->multisample_draw_location = WINED3D_LOCATION_TEXTURE_RGB;
diff --git a/dlls/wined3d/cs.c b/dlls/wined3d/cs.c
index 711c031a028..1bd4e2b4242 100644
--- a/dlls/wined3d/cs.c
+++ b/dlls/wined3d/cs.c
@@ -2123,15 +2123,23 @@ static void wined3d_cs_exec_push_constants(struct wined3d_cs *cs, const void *da
 {
     const struct wined3d_cs_push_constants *op = data;
     struct wined3d_device *device = cs->c.device;
+    unsigned int ffp_start_idx, ffp_end_idx;
     unsigned int context_count, i;
 
     /* The constant buffers were already updated; this op is just to mark the
      * constants as invalid in the device state. */
 
+    ffp_start_idx = op->start_idx / sizeof(struct wined3d_vec4);
+    ffp_end_idx = (op->start_idx + op->count + sizeof(struct wined3d_vec4)) / sizeof(struct wined3d_vec4);
+
     if (op->type == WINED3D_PUSH_CONSTANTS_VS_F)
         device->shader_backend->shader_update_float_vertex_constants(device, op->start_idx, op->count);
     else if (op->type == WINED3D_PUSH_CONSTANTS_PS_F)
         device->shader_backend->shader_update_float_pixel_constants(device, op->start_idx, op->count);
+    else if (op->type == WINED3D_PUSH_CONSTANTS_VS_FFP)
+        device->shader_backend->shader_update_float_vertex_constants(device, ffp_start_idx, ffp_end_idx - ffp_start_idx);
+    else if (op->type == WINED3D_PUSH_CONSTANTS_PS_FFP)
+        device->shader_backend->shader_update_float_pixel_constants(device, ffp_start_idx, ffp_end_idx - ffp_start_idx);
 
     for (i = 0, context_count = device->context_count; i < context_count; ++i)
         device->contexts[i]->constant_update_mask |= op->update_mask;
diff --git a/dlls/wined3d/glsl_shader.c b/dlls/wined3d/glsl_shader.c
index 7ff9ce0427b..785050e7631 100644
--- a/dlls/wined3d/glsl_shader.c
+++ b/dlls/wined3d/glsl_shader.c
@@ -1735,17 +1735,38 @@ static void shader_glsl_load_constants(struct shader_glsl_priv *priv,
     constant_version = prog->constant_version;
     update_mask = context->constant_update_mask & prog->constant_update_mask;
 
-    if (update_mask & WINED3D_SHADER_CONST_VS_F)
-        shader_glsl_load_constants_f(vshader, context_gl, device->push_constants[WINED3D_PUSH_CONSTANTS_VS_F],
-                prog->vs.uniform_f_locations, &priv->vconst_heap, priv->stack, constant_version);
+    if (vshader && vshader->is_ffp_vs)
+    {
+        /* The shader's constant update mask is WINED3D_SHADER_CONST_VS_F.
+         * This may be set from shader_glsl_update_graphics_program().
+         * However, we also need to update constants when FFP flags change. */
+        static const uint32_t vs_update_mask = WINED3D_SHADER_CONST_VS_F
+                | WINED3D_SHADER_CONST_FFP_LIGHTS
+                | WINED3D_SHADER_CONST_FFP_MATERIAL
+                | WINED3D_SHADER_CONST_FFP_MODELVIEW
+                | WINED3D_SHADER_CONST_FFP_PROJ
+                | WINED3D_SHADER_CONST_FFP_TEXMATRIX
+                | WINED3D_SHADER_CONST_FFP_VERTEXBLEND
+                | WINED3D_SHADER_CONST_VS_POINTSIZE;
 
-    if (update_mask & WINED3D_SHADER_CONST_VS_I)
-        shader_glsl_load_constants_i(vshader, context_gl, device->push_constants[WINED3D_PUSH_CONSTANTS_VS_I],
-                prog->vs.uniform_i_locations, vshader->reg_maps.integer_constants);
+        if (context->constant_update_mask & vs_update_mask)
+            shader_glsl_load_constants_f(vshader, context_gl, device->push_constants[WINED3D_PUSH_CONSTANTS_VS_FFP],
+                    prog->vs.uniform_f_locations, &priv->vconst_heap, priv->stack, constant_version);
+    }
+    else
+    {
+        if (update_mask & WINED3D_SHADER_CONST_VS_F)
+            shader_glsl_load_constants_f(vshader, context_gl, device->push_constants[WINED3D_PUSH_CONSTANTS_VS_F],
+                    prog->vs.uniform_f_locations, &priv->vconst_heap, priv->stack, constant_version);
 
-    if (update_mask & WINED3D_SHADER_CONST_VS_B)
-        shader_glsl_load_constants_b(vshader, context_gl, device->push_constants[WINED3D_PUSH_CONSTANTS_VS_B],
-                prog->vs.uniform_b_locations, vshader->reg_maps.boolean_constants);
+        if (update_mask & WINED3D_SHADER_CONST_VS_I)
+            shader_glsl_load_constants_i(vshader, context_gl, device->push_constants[WINED3D_PUSH_CONSTANTS_VS_I],
+                    prog->vs.uniform_i_locations, vshader->reg_maps.integer_constants);
+
+        if (update_mask & WINED3D_SHADER_CONST_VS_B)
+            shader_glsl_load_constants_b(vshader, context_gl, device->push_constants[WINED3D_PUSH_CONSTANTS_VS_B],
+                    prog->vs.uniform_b_locations, vshader->reg_maps.boolean_constants);
+    }
 
     if (update_mask & WINED3D_SHADER_CONST_VS_CLIP_PLANES)
     {
@@ -1890,17 +1911,30 @@ static void shader_glsl_load_constants(struct shader_glsl_priv *priv,
                     WINED3D_LIGHT_PARALLELPOINT, &constants->light.lights[i], prog);
     }
 
-    if (update_mask & WINED3D_SHADER_CONST_PS_F)
-        shader_glsl_load_constants_f(pshader, context_gl, device->push_constants[WINED3D_PUSH_CONSTANTS_PS_F],
-                prog->ps.uniform_f_locations, &priv->pconst_heap, priv->stack, constant_version);
+    if (pshader && pshader->is_ffp_ps)
+    {
+        static const uint32_t ps_update_mask = WINED3D_SHADER_CONST_PS_F
+                | WINED3D_SHADER_CONST_FFP_COLOR_KEY
+                | WINED3D_SHADER_CONST_FFP_PS;
 
-    if (update_mask & WINED3D_SHADER_CONST_PS_I)
-        shader_glsl_load_constants_i(pshader, context_gl, device->push_constants[WINED3D_PUSH_CONSTANTS_PS_I],
-                prog->ps.uniform_i_locations, pshader->reg_maps.integer_constants);
+        if (context->constant_update_mask & ps_update_mask)
+            shader_glsl_load_constants_f(pshader, context_gl, device->push_constants[WINED3D_PUSH_CONSTANTS_PS_FFP],
+                    prog->ps.uniform_f_locations, &priv->pconst_heap, priv->stack, constant_version);
+    }
+    else
+    {
+        if (update_mask & WINED3D_SHADER_CONST_PS_F)
+            shader_glsl_load_constants_f(pshader, context_gl, device->push_constants[WINED3D_PUSH_CONSTANTS_PS_F],
+                    prog->ps.uniform_f_locations, &priv->pconst_heap, priv->stack, constant_version);
 
-    if (update_mask & WINED3D_SHADER_CONST_PS_B)
-        shader_glsl_load_constants_b(pshader, context_gl, device->push_constants[WINED3D_PUSH_CONSTANTS_PS_B],
-                prog->ps.uniform_b_locations, pshader->reg_maps.boolean_constants);
+        if (update_mask & WINED3D_SHADER_CONST_PS_I)
+            shader_glsl_load_constants_i(pshader, context_gl, device->push_constants[WINED3D_PUSH_CONSTANTS_PS_I],
+                    prog->ps.uniform_i_locations, pshader->reg_maps.integer_constants);
+
+        if (update_mask & WINED3D_SHADER_CONST_PS_B)
+            shader_glsl_load_constants_b(pshader, context_gl, device->push_constants[WINED3D_PUSH_CONSTANTS_PS_B],
+                    prog->ps.uniform_b_locations, pshader->reg_maps.boolean_constants);
+    }
 
     if (update_mask & WINED3D_SHADER_CONST_PS_BUMP_ENV)
     {
@@ -12113,7 +12147,7 @@ static void glsl_fragment_pipe_fogparams(struct wined3d_context *context,
 static void glsl_fragment_pipe_fog(struct wined3d_context *context,
         const struct wined3d_state *state, DWORD state_id)
 {
-    BOOL use_vshader = use_vs(state);
+    BOOL use_vshader = use_vs(state) && !state->shader[WINED3D_SHADER_TYPE_VERTEX]->is_ffp_vs;
     enum fogsource new_source;
     DWORD fogstart = state->render_states[WINED3D_RS_FOGSTART];
     DWORD fogend = state->render_states[WINED3D_RS_FOGEND];
diff --git a/dlls/wined3d/wined3d_main.c b/dlls/wined3d/wined3d_main.c
index 863428bb53a..3b436919559 100644
--- a/dlls/wined3d/wined3d_main.c
+++ b/dlls/wined3d/wined3d_main.c
@@ -463,6 +463,11 @@ static BOOL wined3d_dll_init(HINSTANCE hInstDLL)
             TRACE("Forcing all constant buffers to be write-mappable.\n");
             wined3d_settings.cb_access_map_w = TRUE;
         }
+        if (!get_config_key_dword(hkey, appkey, env, "ffp_hlsl", &tmpvalue))
+        {
+            ERR_(winediag)("Using the HLSL-based FFP backend.\n");
+            wined3d_settings.ffp_hlsl = tmpvalue;
+        }
     }
 
     if (appkey) RegCloseKey( appkey );
diff --git a/dlls/wined3d/wined3d_private.h b/dlls/wined3d/wined3d_private.h
index bb593a94fa2..12b61b68bbb 100644
--- a/dlls/wined3d/wined3d_private.h
+++ b/dlls/wined3d/wined3d_private.h
@@ -476,7 +476,6 @@ struct wined3d_settings
     char *logo;
     unsigned int multisample_textures;
     unsigned int sample_count;
-    BOOL check_float_constants;
     unsigned int strict_shader_math;
     unsigned int max_sm_vs;
     unsigned int max_sm_hs;
@@ -486,7 +485,9 @@ struct wined3d_settings
     unsigned int max_sm_cs;
     enum wined3d_renderer renderer;
     enum wined3d_shader_backend shader_backend;
-    BOOL cb_access_map_w;
+    bool check_float_constants;
+    bool cb_access_map_w;
+    bool ffp_hlsl;
 };
 
 extern struct wined3d_settings wined3d_settings;