diff --git a/crates/snapbox/src/data/mod.rs b/crates/snapbox/src/data/mod.rs
index 56a5803d..20e9cca3 100644
--- a/crates/snapbox/src/data/mod.rs
+++ b/crates/snapbox/src/data/mod.rs
@@ -161,7 +161,8 @@ impl Data {
     pub fn read_from(path: &std::path::Path, data_format: Option<DataFormat>) -> Self {
         match Self::try_read_from(path, data_format) {
             Ok(data) => data,
-            Err(err) => Self::error(err, data_format.unwrap_or_default()).with_path(path),
+            Err(err) => Self::error(err, data_format.unwrap_or_else(|| DataFormat::from(path)))
+                .with_path(path),
         }
     }
 
diff --git a/crates/snapbox/src/data/normalize.rs b/crates/snapbox/src/data/normalize.rs
index ca0455ca..afa3229e 100644
--- a/crates/snapbox/src/data/normalize.rs
+++ b/crates/snapbox/src/data/normalize.rs
@@ -79,10 +79,12 @@ impl Normalize for NormalizeMatches<'_> {
             DataInner::Error(err) => err.into(),
             DataInner::Binary(bin) => Data::binary(bin),
             DataInner::Text(text) => {
-                let lines = self
-                    .substitutions
-                    .normalize(&text, &self.pattern.render().unwrap());
-                Data::text(lines)
+                if let Some(pattern) = self.pattern.render() {
+                    let lines = self.substitutions.normalize(&text, &pattern);
+                    Data::text(lines)
+                } else {
+                    DataInner::Text(text).into()
+                }
             }
             #[cfg(feature = "json")]
             DataInner::Json(value) => {
@@ -94,10 +96,12 @@ impl Normalize for NormalizeMatches<'_> {
             }
             #[cfg(feature = "term-svg")]
             DataInner::TermSvg(text) => {
-                let lines = self
-                    .substitutions
-                    .normalize(&text, &self.pattern.render().unwrap());
-                DataInner::TermSvg(lines).into()
+                if let Some(pattern) = self.pattern.render() {
+                    let lines = self.substitutions.normalize(&text, &pattern);
+                    DataInner::TermSvg(lines).into()
+                } else {
+                    DataInner::TermSvg(text).into()
+                }
             }
         };
         new.source = data.source;