diff --git a/executable_semantics/BUILD b/executable_semantics/BUILD
index b2f594e1d3f3..6bde92b321a6 100644
--- a/executable_semantics/BUILD
+++ b/executable_semantics/BUILD
@@ -35,6 +35,7 @@ cc_binary(
     srcs = ["main_bin.cpp"],
     deps = [
         ":main",
+        "@llvm-project//llvm:Support",
     ],
 )
 
diff --git a/executable_semantics/main_bin.cpp b/executable_semantics/main_bin.cpp
index 11a3a4d9f427..c3b133309716 100644
--- a/executable_semantics/main_bin.cpp
+++ b/executable_semantics/main_bin.cpp
@@ -3,9 +3,29 @@
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 
 #include "executable_semantics/main.h"
+#include "llvm/ADT/SmallString.h"
+#include "llvm/Support/FileSystem.h"
+#include "llvm/Support/Path.h"
 
 auto main(int argc, char** argv) -> int {
   // This assumes execution from bazel, in runfiles.
-  return Carbon::ExecutableSemanticsMain(
-      "executable_semantics/data/prelude.carbon", argc, argv);
+  llvm::SmallString<256> prelude_path;
+  if (std::error_code err = llvm::sys::fs::current_path(prelude_path)) {
+    llvm::errs() << "Failed to get working directory: " << err.message();
+    return 1;
+  }
+  llvm::sys::path::append(prelude_path,
+                          "executable_semantics/data/prelude.carbon");
+
+  // Behave as if the working directory is where `bazel run` was invoked.
+  char* build_working_dir = getenv("BUILD_WORKING_DIRECTORY");
+  if (build_working_dir != nullptr) {
+    if (std::error_code err =
+            llvm::sys::fs::set_current_path(build_working_dir)) {
+      llvm::errs() << "Failed to set working directory: " << err.message();
+      return 1;
+    }
+  }
+
+  return Carbon::ExecutableSemanticsMain(prelude_path, argc, argv);
 }