diff --git a/simgear/screen/extensions.cxx b/simgear/screen/extensions.cxx
index c16509f6..75f7d11e 100644
--- a/simgear/screen/extensions.cxx
+++ b/simgear/screen/extensions.cxx
@@ -26,7 +26,7 @@
 
 #include "extensions.hxx"
 
-bool SGSearchExtensionsString(char *extString, char *extName) {
+static bool SGSearchExtensionsString(char *extString, char *extName) {
     // Returns GL_TRUE if the *extName string appears in the *extString string,
     // surrounded by white spaces, or GL_FALSE otherwise.
 
diff --git a/simgear/screen/extensions.hxx b/simgear/screen/extensions.hxx
index 43a7e348..8fd83c6e 100644
--- a/simgear/screen/extensions.hxx
+++ b/simgear/screen/extensions.hxx
@@ -41,7 +41,7 @@ extern "C" {
 #define APIENTRY
 #endif
 
-static bool SGSearchExtensionsString(char *extString, char *extName);
+    // static bool SGSearchExtensionsString(char *extString, char *extName);
 bool SGIsOpenGLExtensionSupported(char *extName);
 
 #ifdef __APPLE__