diff --git a/vlib/compiler/cgen.v b/vlib/compiler/cgen.v
index 2ec93beb39..d99d90fa9c 100644
--- a/vlib/compiler/cgen.v
+++ b/vlib/compiler/cgen.v
@@ -267,6 +267,11 @@ fn build_thirdparty_obj_file(path string, moduleflags []CFlag) {
 		verror(err)
 		return
 	}
+	if res.exit_code != 0 {
+		println('failed thirdparty object build cmd: $cmd')
+		verror(res.output)
+		return
+	}
 	println(res.output)
 }
 
diff --git a/vlib/compiler/msvc.v b/vlib/compiler/msvc.v
index 2422e2e57f..b6128ac721 100644
--- a/vlib/compiler/msvc.v
+++ b/vlib/compiler/msvc.v
@@ -414,9 +414,15 @@ fn build_thirdparty_obj_file_with_msvc(path string, moduleflags []CFlag) {
 	//NB: the quotes above ARE balanced.
 	println('thirdparty cmd line: $cmd')
 	res := os.exec(cmd) or {
+		println('msvc: failed thirdparty object build cmd: $cmd')
 		verror(err)
 		return
 	}
+	if res.exit_code != 0 {
+		println('msvc: failed thirdparty object build cmd: $cmd')
+		verror(res.output)
+		return
+	}
 	println(res.output)
 }