diff --git a/vlib/compiler/comptime.v b/vlib/compiler/comptime.v
index d10ee01e3c..e4b28fbc57 100644
--- a/vlib/compiler/comptime.v
+++ b/vlib/compiler/comptime.v
@@ -201,6 +201,11 @@ fn (p mut Parser) chash() {
 	}
 	if hash.starts_with('include') {
 		if p.first_pass() && !p.is_vh {
+			if !p.pref.building_v && !p.fileis('vlib') {
+				p.warn('C #includes will soon be removed from the language' +
+				'\ndefine the C structs and functions in V')
+				
+			}	
 			if p.file_pcguard.len != 0 {
 				//println('p: $p.file_platform $p.file_pcguard')
 				p.cgen.includes << '$p.file_pcguard\n#$hash\n#endif'
diff --git a/vlib/compiler/struct.v b/vlib/compiler/struct.v
index 2326b0e70e..e085545d89 100644
--- a/vlib/compiler/struct.v
+++ b/vlib/compiler/struct.v
@@ -37,6 +37,11 @@ fn (p mut Parser) struct_decl() {
 	}
 	is_c := name == 'C' && p.tok == .dot
 	if is_c {
+		if !p.pref.building_v && !p.fileis('vlib') {
+			p.warn('Virtual C structs will soon be removed from the language' +
+			'\ndefine the C structs and functions in V')
+		}
+				
 		p.check(.dot)
 		name = p.check_name()
 		cat = .c_struct