diff --git a/.github/workflows/rust.yml b/.github/workflows/rust.yml
index f5b4211c..4a3a6441 100644
--- a/.github/workflows/rust.yml
+++ b/.github/workflows/rust.yml
@@ -15,7 +15,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        rust: [stable, beta, nightly]
+        rust: [stable, beta, nightly, 1.58.1]
     steps:
       - uses: actions/checkout@v2
       - uses: actions-rs/toolchain@v1
diff --git a/dotenv/src/iter.rs b/dotenv/src/iter.rs
index 52c86dd0..6b9f2bc8 100644
--- a/dotenv/src/iter.rs
+++ b/dotenv/src/iter.rs
@@ -114,7 +114,9 @@ impl<B: BufRead> Iterator for QuotedLines<B> {
                     if buf.trim_start().starts_with('#') {
                         return Some(Ok(String::with_capacity(0)));
                     }
-                    (cur_pos, cur_state) = eval_end_state(cur_state, &buf[buf_pos..]);
+                    let result = eval_end_state(cur_state, &buf[buf_pos..]);
+                    cur_pos = result.0;
+                    cur_state = result.1;
 
                     match cur_state {
                         ParseState::Complete => {