diff --git a/cli/ops/runtime_compiler.rs b/cli/ops/runtime_compiler.rs
index 481b29a110..60aa07bdd3 100644
--- a/cli/ops/runtime_compiler.rs
+++ b/cli/ops/runtime_compiler.rs
@@ -10,6 +10,7 @@ use crate::specifier_handler::MemoryHandler;
 use crate::specifier_handler::SpecifierHandler;
 
 use deno_core::error::generic_error;
+use deno_core::error::type_error;
 use deno_core::error::AnyError;
 use deno_core::error::Context;
 use deno_core::serde_json;
@@ -55,6 +56,7 @@ async fn op_emit(
 ) -> Result<Value, AnyError> {
   deno_runtime::ops::check_unstable2(&state, "Deno.emit");
   let args: EmitArgs = serde_json::from_value(args)?;
+  let root_specifier = args.root_specifier;
   let program_state = state.borrow().borrow::<Arc<ProgramState>>().clone();
   let runtime_permissions = {
     let state = state.borrow();
@@ -92,9 +94,16 @@ async fn op_emit(
     None
   };
   let mut builder = GraphBuilder::new(handler, maybe_import_map, None);
-  let root_specifier =
-    ModuleSpecifier::resolve_url_or_path(&args.root_specifier)?;
-  builder.add(&root_specifier, is_dynamic).await?;
+  let root_specifier = ModuleSpecifier::resolve_url_or_path(&root_specifier)?;
+  builder
+    .add(&root_specifier, is_dynamic)
+    .await
+    .map_err(|_| {
+      type_error(format!(
+        "Unable to handle the given specifier: {}",
+        &root_specifier
+      ))
+    })?;
   let bundle_type = match args.bundle {
     Some(RuntimeBundleType::Esm) => BundleType::Esm,
     _ => BundleType::None,
diff --git a/cli/tests/compiler_api_test.ts b/cli/tests/compiler_api_test.ts
index 17c02b0e50..99c7af9616 100644
--- a/cli/tests/compiler_api_test.ts
+++ b/cli/tests/compiler_api_test.ts
@@ -292,3 +292,16 @@ Deno.test({
     assert(diagnostics[0].messageText.includes("This import is never used"));
   },
 });
+
+Deno.test({
+  name: "Deno.emit() - Unknown media type does not panic",
+  async fn() {
+    await assertThrowsAsync(async () => {
+      await Deno.emit("https://example.com/foo", {
+        sources: {
+          "https://example.com/foo": `let foo: string = "foo";`,
+        },
+      });
+    });
+  },
+});