diff --git a/test/benchmark/mandelbrot/README.md b/test/benchmark/mandelbrot/README.md
index 02f89c2..5fc5a83 100644
--- a/test/benchmark/mandelbrot/README.md
+++ b/test/benchmark/mandelbrot/README.md
@@ -14,7 +14,7 @@ TODO
 
 ```sh
 wasicc -O3 -s mandel_dd.c -o mandel_dd.wasm
-wasicc -O3 -s mandel.c -o mandel.wasm -Wl,-lc-printscan-long-double
+wasicc -O3 -s mandel.c -o mandel.wasm
 ```
 
 ### Running
diff --git a/test/benchmark/mandelbrot/mandel.c b/test/benchmark/mandelbrot/mandel.c
index 3dc3ca3..89237fa 100644
--- a/test/benchmark/mandelbrot/mandel.c
+++ b/test/benchmark/mandelbrot/mandel.c
@@ -21,7 +21,7 @@ int main(int argc, char **argv) {
     } else if (argc == 3) {
         width = atoi(argv[1]);
         height = width;
-        magn = strtold(argv[2], NULL);
+        magn = strtod(argv[2], NULL);
     } else {
         fprintf(stderr, "usage: %s <size> <magnification>\n", argv[0]);
         return 1;
diff --git a/test/benchmark/mandelbrot/mandel.wasm b/test/benchmark/mandelbrot/mandel.wasm
index dafd491..559c5f9 100755
Binary files a/test/benchmark/mandelbrot/mandel.wasm and b/test/benchmark/mandelbrot/mandel.wasm differ