diff --git a/contrib/local.mk.example b/contrib/local.mk.example
index c8ccf8c03f..12297eceba 100644
--- a/contrib/local.mk.example
+++ b/contrib/local.mk.example
@@ -4,16 +4,25 @@
 # By default, the installation prefix is '/usr/local'.
 # CMAKE_EXTRA_FLAGS += -DCMAKE_INSTALL_PREFIX=/usr/local/neovim-latest
 
+# These CFLAGS can be used in addition to those specified in CMakeLists.txt:
+# CMAKE_EXTRA_FLAGS="-DCMAKE_C_FLAGS=-ftrapv -Wlogical-op"
+
+# By default, the jemalloc family of memory allocation functions are used.
+# Uncomment the following to instead use libc memory allocation functions:
+# CMAKE_EXTRA_FLAGS="-DUSE_JEMALLOC=OFF"
+
 # Sets the build type; defaults to Debug. Valid values:
 #
 # - Debug:          Disables optimizations (-O0), enables debug information.
 #
-# - RelWithDebInfo: Enables optimizations that do not interfere with debugging
-#                   (-O2) which do, enables debug information.
+# - RelWithDebInfo: Enables all optimizations that do not interfere with
+#                   debugging (-Og if available, -O2 and -g if not).
+#                   Enables debug information.
 #
 # - MinSizeRel:     Enables all -O2 optimization that do not typically
 #                   increase code size, and performs further optimizations
-#                   designed to reduce code size. Disables debug information.
+#                   designed to reduce code size (-Os).
+#                   Disables debug information.
 #
 # - Release:        Same as RelWithDebInfo, but disables debug information.
 #