diff --git a/configure.in b/configure.in
index 23d3d7c8327..35dd35be2c9 100644
--- a/configure.in
+++ b/configure.in
@@ -7905,6 +7905,10 @@ if test "$MOZ_TREE_CAIRO"; then
     MOZ_CAIRO_CFLAGS='-I$(LIBXUL_DIST)/include/cairo'
     AC_DEFINE(MOZ_TREE_CAIRO)
 
+    # For now we assume that we will have a uint64_t available through
+    # one of the above headers or mozstdint.h.
+    AC_DEFINE(HAVE_UINT64_T)
+
     # Define macros for cairo-features.h
     TEE_SURFACE_FEATURE="#define CAIRO_HAS_TEE_SURFACE 1"
     if test "$MOZ_X11"; then