diff --git a/.changeset/clean-ligers-reply.md b/.changeset/clean-ligers-reply.md
new file mode 100644
index 00000000..bbedf0e8
--- /dev/null
+++ b/.changeset/clean-ligers-reply.md
@@ -0,0 +1,5 @@
+---
+'nxjs-runtime': patch
+---
+
+Log unhandled errors / promise rejections to the debug log file
diff --git a/source/error.c b/source/error.c
index c7317856..bcd6d2ba 100644
--- a/source/error.c
+++ b/source/error.c
@@ -6,14 +6,13 @@ void print_js_error(JSContext *ctx)
     const char *exception_str = JS_ToCString(ctx, exception_val);
     printf("%s\n", exception_str);
     fprintf(stderr, "%s\n", exception_str);
-    fflush(stderr);
     JS_FreeCString(ctx, exception_str);
 
     JSValue stack_val = JS_GetPropertyStr(ctx, exception_val, "stack");
     const char *stack_str = JS_ToCString(ctx, stack_val);
     printf("%s\n", stack_str);
     fprintf(stderr, "%s\n", stack_str);
-    fflush(stderr);
+
     JS_FreeCString(ctx, stack_str);
     JS_FreeValue(ctx, exception_val);
     JS_FreeValue(ctx, stack_val);
@@ -23,6 +22,20 @@ void nx_emit_error_event(JSContext *ctx)
 {
     JSValue exception_val = JS_GetException(ctx);
     nx_context_t *nx_ctx = JS_GetContextOpaque(ctx);
+
+    // Print the error to stderr so that it ends up in the log file
+    const char *exception_str = JS_ToCString(ctx, exception_val);
+    fprintf(stderr, "Uncaught %s\n", exception_str);
+    JS_FreeCString(ctx, exception_str);
+
+    JSValue stack_val = JS_GetPropertyStr(ctx, exception_val, "stack");
+    if (!JS_IsUndefined(stack_val)) {
+        const char *stack_str = JS_ToCString(ctx, stack_val);
+        fprintf(stderr, "%s\n", stack_str);
+        JS_FreeCString(ctx, stack_str);
+        JS_FreeValue(ctx, stack_val);
+    }
+
     JSValueConst args[] = {exception_val};
     JSValue ret_val = JS_Call(ctx, nx_ctx->error_handler, JS_NULL, 1, args);
     if (JS_IsException(ret_val))
@@ -52,6 +65,20 @@ void nx_promise_rejection_handler(JSContext *ctx, JSValueConst promise,
                                   JS_BOOL is_handled, void *opaque)
 {
     nx_context_t *nx_ctx = JS_GetContextOpaque(ctx);
+
+    // Print the error to stderr so that it ends up in the log file
+    const char *exception_str = JS_ToCString(ctx, reason);
+    fprintf(stderr, "Uncaught (in promise) %s\n", exception_str);
+    JS_FreeCString(ctx, exception_str);
+
+    JSValue stack_val = JS_GetPropertyStr(ctx, reason, "stack");
+    if (!JS_IsUndefined(stack_val)) {
+        const char *stack_str = JS_ToCString(ctx, stack_val);
+        fprintf(stderr, "%s\n", stack_str);
+        JS_FreeCString(ctx, stack_str);
+        JS_FreeValue(ctx, stack_val);
+    }
+
     JSValueConst args[] = {promise, reason};
     JSValue ret_val = JS_Call(ctx, nx_ctx->unhandled_rejection_handler, JS_NULL, 2, args);
     if (JS_IsException(ret_val))