diff --git a/libs/vkd3d-shader/ir.c b/libs/vkd3d-shader/ir.c
index 121b0fe3..c6ecbdd9 100644
--- a/libs/vkd3d-shader/ir.c
+++ b/libs/vkd3d-shader/ir.c
@@ -5753,6 +5753,32 @@ static void vsir_validate_instruction(struct validation_context *ctx)
         case VKD3DSIH_DCL_OUTPUT:
             return;
 
+        case VKD3DSIH_DCL_INPUT_PRIMITIVE:
+            if (instruction->declaration.primitive_type.type == VKD3D_PT_UNDEFINED
+                    || instruction->declaration.primitive_type.type >= VKD3D_PT_COUNT)
+                validator_error(ctx, VKD3D_SHADER_ERROR_VSIR_INVALID_GS, "GS input primitive %u is invalid.",
+                        instruction->declaration.primitive_type.type);
+            return;
+
+        case VKD3DSIH_DCL_VERTICES_OUT:
+            if (instruction->declaration.count > 1024)
+                validator_error(ctx, VKD3D_SHADER_ERROR_VSIR_INVALID_GS, "GS output vertex count %u is invalid.",
+                        instruction->declaration.count);
+            return;
+
+        case VKD3DSIH_DCL_OUTPUT_TOPOLOGY:
+            if (instruction->declaration.primitive_type.type == VKD3D_PT_UNDEFINED
+                    || instruction->declaration.primitive_type.type >= VKD3D_PT_COUNT)
+                validator_error(ctx, VKD3D_SHADER_ERROR_VSIR_INVALID_GS, "GS output primitive %u is invalid.",
+                        instruction->declaration.primitive_type.type);
+            return;
+
+        case VKD3DSIH_DCL_GS_INSTANCES:
+            if (!instruction->declaration.count || instruction->declaration.count > 32)
+                validator_error(ctx, VKD3D_SHADER_ERROR_VSIR_INVALID_GS, "GS instance count %u is invalid.",
+                        instruction->declaration.count);
+            return;
+
         case VKD3DSIH_DCL_OUTPUT_CONTROL_POINT_COUNT:
             if (!instruction->declaration.count || instruction->declaration.count > 32)
                 validator_error(ctx, VKD3D_SHADER_ERROR_VSIR_INVALID_TESSELLATION, "Output control point count %u is invalid.",
diff --git a/libs/vkd3d-shader/vkd3d_shader_private.h b/libs/vkd3d-shader/vkd3d_shader_private.h
index a56c6898..3951ca70 100644
--- a/libs/vkd3d-shader/vkd3d_shader_private.h
+++ b/libs/vkd3d-shader/vkd3d_shader_private.h
@@ -223,6 +223,7 @@ enum vkd3d_shader_error
     VKD3D_SHADER_ERROR_VSIR_INVALID_CONTROL_FLOW        = 9016,
     VKD3D_SHADER_ERROR_VSIR_INVALID_SSA_USAGE           = 9017,
     VKD3D_SHADER_ERROR_VSIR_INVALID_TESSELLATION        = 9018,
+    VKD3D_SHADER_ERROR_VSIR_INVALID_GS                  = 9019,
 
     VKD3D_SHADER_WARNING_VSIR_DYNAMIC_DESCRIPTOR_ARRAY  = 9300,
 };