diff --git a/src/egl/main/eglapi.c b/src/egl/main/eglapi.c
index 2fdf5d73a61..95a5e76adf1 100644
--- a/src/egl/main/eglapi.c
+++ b/src/egl/main/eglapi.c
@@ -934,6 +934,8 @@ _eglNativeSurfaceAlreadyUsed(_EGLDisplay *disp, void *native_surface)
 {
    _EGLResource *list;
 
+   simple_mtx_assert_locked(&disp->Mutex);
+
    list = disp->ResourceLists[_EGL_RESOURCE_SURFACE];
    while (list) {
       _EGLSurface *surf = (_EGLSurface *) list;
diff --git a/src/egl/main/egldisplay.c b/src/egl/main/egldisplay.c
index 9afa0e3d1a2..db90b2b2dc7 100644
--- a/src/egl/main/egldisplay.c
+++ b/src/egl/main/egldisplay.c
@@ -313,6 +313,8 @@ _eglReleaseDisplayResources(_EGLDisplay *display)
    _EGLResource *list;
    const _EGLDriver *drv = display->Driver;
 
+   simple_mtx_assert_locked(&display->Mutex);
+
    list = display->ResourceLists[_EGL_RESOURCE_CONTEXT];
    while (list) {
       _EGLContext *ctx = (_EGLContext *) list;
@@ -400,6 +402,8 @@ _eglCheckResource(void *res, _EGLResourceType type, _EGLDisplay *disp)
 {
    _EGLResource *list = disp->ResourceLists[type];
    
+   simple_mtx_assert_locked(&disp->Mutex);
+
    if (!res)
       return EGL_FALSE;
 
@@ -462,6 +466,7 @@ void
 _eglLinkResource(_EGLResource *res, _EGLResourceType type)
 {
    assert(res->Display);
+   simple_mtx_assert_locked(&res->Display->Mutex);
 
    res->IsLinked = EGL_TRUE;
    res->Next = res->Display->ResourceLists[type];
@@ -478,6 +483,8 @@ _eglUnlinkResource(_EGLResource *res, _EGLResourceType type)
 {
    _EGLResource *prev;
 
+   simple_mtx_assert_locked(&res->Display->Mutex);
+
    prev = res->Display->ResourceLists[type];
    if (prev != res) {
       while (prev) {