diff --git a/src/amd/vulkan/radv_shader.h b/src/amd/vulkan/radv_shader.h
index 10370353da8..5e25261361f 100644
--- a/src/amd/vulkan/radv_shader.h
+++ b/src/amd/vulkan/radv_shader.h
@@ -577,9 +577,11 @@ get_tcs_num_patches(unsigned tcs_num_input_vertices,
 	if (chip_class >= GFX7 && family != CHIP_STONEY)
 		hardware_lds_size = 65536;
 
-	num_patches = MIN2(num_patches, hardware_lds_size / (input_patch_size + output_patch_size));
+	if (input_patch_size + output_patch_size)
+		num_patches = MIN2(num_patches, hardware_lds_size / (input_patch_size + output_patch_size));
 	/* Make sure the output data fits in the offchip buffer */
-	num_patches = MIN2(num_patches, (tess_offchip_block_dw_size * 4) / output_patch_size);
+	if (output_patch_size)
+		num_patches = MIN2(num_patches, (tess_offchip_block_dw_size * 4) / output_patch_size);
 	/* Not necessary for correctness, but improves performance. The
 	 * specific value is taken from the proprietary driver.
 	 */