diff --git a/cli/tests/integration/fmt_tests.rs b/cli/tests/integration/fmt_tests.rs
index 144c2b56ca..d230f96c07 100644
--- a/cli/tests/integration/fmt_tests.rs
+++ b/cli/tests/integration/fmt_tests.rs
@@ -189,6 +189,12 @@ itest!(fmt_check_parse_error {
   exit_code: 1,
 });
 
+itest!(fmt_check_invalid_data {
+  args: "fmt --check fmt/invalid_data.json",
+  output: "fmt/invalid_data.out",
+  exit_code: 1,
+});
+
 itest!(fmt_stdin {
   args: "fmt -",
   input: Some("const a = 1\n"),
diff --git a/cli/tests/testdata/fmt/invalid_data.json b/cli/tests/testdata/fmt/invalid_data.json
new file mode 100644
index 0000000000..fb9bec94fe
Binary files /dev/null and b/cli/tests/testdata/fmt/invalid_data.json differ
diff --git a/cli/tests/testdata/fmt/invalid_data.out b/cli/tests/testdata/fmt/invalid_data.out
new file mode 100644
index 0000000000..7fd5046ee7
--- /dev/null
+++ b/cli/tests/testdata/fmt/invalid_data.out
@@ -0,0 +1 @@
+error: [WILDCARD] is not a valid UTF-8 file
diff --git a/cli/tools/fmt.rs b/cli/tools/fmt.rs
index f16e307310..d987d02d64 100644
--- a/cli/tools/fmt.rs
+++ b/cli/tools/fmt.rs
@@ -20,6 +20,7 @@ use crate::util::fs::FileCollector;
 use crate::util::path::get_extension;
 use crate::util::text_encoding;
 use deno_ast::ParsedSource;
+use deno_core::anyhow::anyhow;
 use deno_core::anyhow::bail;
 use deno_core::anyhow::Context;
 use deno_core::error::generic_error;
@@ -574,7 +575,10 @@ fn read_file_contents(file_path: &Path) -> Result<FileContents, AnyError> {
   let file_bytes = fs::read(file_path)
     .with_context(|| format!("Error reading {}", file_path.display()))?;
   let charset = text_encoding::detect_charset(&file_bytes);
-  let file_text = text_encoding::convert_to_utf8(&file_bytes, charset)?;
+  let file_text = text_encoding::convert_to_utf8(&file_bytes, charset)
+    .map_err(|_| {
+      anyhow!("{} is not a valid UTF-8 file", file_path.display())
+    })?;
   let had_bom = file_text.starts_with(text_encoding::BOM_CHAR);
   let text = if had_bom {
     text_encoding::strip_bom(&file_text).to_string()