diff --git a/src/shell.rs b/src/shell.rs
index 36b0982..959885d 100644
--- a/src/shell.rs
+++ b/src/shell.rs
@@ -235,7 +235,10 @@ pub fn command_output(shell: &str, command: &str) -> String {
 		.output()
 		.expect("failed to execute process");
 
-	String::from_utf8_lossy(&output.stdout).to_string()
+		match output.stdout.is_empty() {
+			false => String::from_utf8_lossy(&output.stdout).to_lowercase(),
+			true => String::from_utf8_lossy(&output.stderr).to_lowercase(),
+	}
 }
 
 pub fn last_command(shell: &str) -> String {