diff --git a/libhwcomposer/hwc.cpp b/libhwcomposer/hwc.cpp
index f3911cd..4a8d24d 100644
--- a/libhwcomposer/hwc.cpp
+++ b/libhwcomposer/hwc.cpp
@@ -176,6 +176,7 @@
     switch(dpy) {
         case HWC_DISPLAY_PRIMARY:
             if(blank) {
+                Locker::Autolock _l(ctx->mBlankLock);
                 ctx->mOverlay->setState(ovutils::OV_CLOSED);
                 ret = ioctl(m->framebuffer->fd, FBIOBLANK, FB_BLANK_POWERDOWN);
             } else {
@@ -275,6 +276,7 @@
 {
     int ret = 0;
     hwc_context_t* ctx = (hwc_context_t*)(dev);
+    Locker::Autolock _l(ctx->mBlankLock);
     if(!ctx->overlayInUse)
         ctx->mOverlay->setState(ovutils::OV_CLOSED);
 
diff --git a/libhwcomposer/hwc_utils.h b/libhwcomposer/hwc_utils.h
index db79e7d..07318bd 100644
--- a/libhwcomposer/hwc_utils.h
+++ b/libhwcomposer/hwc_utils.h
@@ -21,6 +21,7 @@
 #define HWC_REMOVE_DEPRECATED_VERSIONS 1
 #include <fcntl.h>
 #include <hardware/hwcomposer.h>
+#include <gr.h>
 #include <gralloc_priv.h>
 
 #define ALIGN_TO(x, align)     (((x) + ((align)-1)) & ~((align)-1))
@@ -182,6 +183,9 @@
 
     //Display in secure mode indicator
     bool mSecureMode;
+
+    //Lock to prevent set from being called while blanking
+    mutable Locker mBlankLock;
 };
 
 #endif //HWC_UTILS_H