diff --git a/glfw/glfw.py b/glfw/glfw.py
index 41c36daaa..c40463b38 100755
--- a/glfw/glfw.py
+++ b/glfw/glfw.py
@@ -55,7 +55,7 @@ def wayland_protocol_file_name(base: str, ext: str = 'c') -> str:
 
 def init_env(env: Env, pkg_config: Callable, at_least_version: Callable, test_compile: Callable, module: str = 'x11') -> Env:
     ans = env.copy()
-    ans.cflags.append('-fpic')
+    ans.cflags.append('-fPIC')
     ans.cppflags.append('-D_GLFW_' + module.upper())
     ans.cppflags.append('-D_GLFW_BUILD_DLL')