diff --git a/src/egl/main/eglglobals.c b/src/egl/main/eglglobals.c
index 0d7270333ec..5760edc3d3c 100644
--- a/src/egl/main/eglglobals.c
+++ b/src/egl/main/eglglobals.c
@@ -161,10 +161,10 @@ _eglGetClientExtensionString(void)
 EGLBoolean
 _eglPointerIsDereferencable(void *p)
 {
-#ifdef HAVE_MINCORE
    uintptr_t addr = (uintptr_t) p;
-   unsigned char valid = 0;
    const long page_size = getpagesize();
+#ifdef HAVE_MINCORE
+   unsigned char valid = 0;
 
    if (p == NULL)
       return EGL_FALSE;
@@ -190,6 +190,7 @@ _eglPointerIsDereferencable(void *p)
     */
    return EGL_TRUE;
 #else
-   return p != NULL;
+   // Without mincore(), we just assume that the first page is unmapped.
+   return addr >= page_size;
 #endif
 }