diff --git a/src/lib.rs b/src/lib.rs
index 7daea19..7b2bc79 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -179,7 +179,10 @@ pub fn parse(text: &str) -> ParseResult<VecDeque<Line>> {
         }
 
         // Parse command component.
-        let end_idx = find_index(line, ' ', idx).unwrap();
+        let end_idx = match find_index(line, ' ', idx) {
+            Some(val) => val,
+            None => return Err(ParseError { details: "Couldn't find index of ' '".to_string() }),
+        };
         let command = &line[idx..end_idx];
         idx = end_idx + 1;