diff --git a/src/backend/external_plugin_cache.rs b/src/backend/external_plugin_cache.rs
index 2b1a28e59c..0f0d328c59 100644
--- a/src/backend/external_plugin_cache.rs
+++ b/src/backend/external_plugin_cache.rs
@@ -84,7 +84,7 @@ fn render_cache_key(config: &Config, tv: &ToolVersion, cache_key: &[String]) ->
             let s = s.trim().to_string();
             trace!("cache key element: {} -> {}", tmpl.trim(), s);
             let mut s = hash_to_str(&s);
-            s.truncate(10);
+            s = s.chars().take(10).collect();
             s
         })
         .collect::<Vec<String>>();
diff --git a/src/config/config_file/mod.rs b/src/config/config_file/mod.rs
index dfdf9c27b0..a60471b6f4 100644
--- a/src/config/config_file/mod.rs
+++ b/src/config/config_file/mod.rs
@@ -467,7 +467,7 @@ fn hashed_path_filename(path: &Path) -> String {
     let hash = hash_to_str(&canonicalized_path);
     let trunc_str = |s: &OsStr| {
         let mut s = s.to_str().unwrap().to_string();
-        s.truncate(20);
+        s = s.chars().take(20).collect();
         s
     };
     let trust_path = dirs::TRUSTED_CONFIGS.join(hash_to_str(&hash));