diff --git a/third_party/jitterentropy/CMakeLists.txt b/third_party/jitterentropy/CMakeLists.txt
index 82f30606b9c..0ed44330a35 100644
--- a/third_party/jitterentropy/CMakeLists.txt
+++ b/third_party/jitterentropy/CMakeLists.txt
@@ -24,7 +24,7 @@ if(WIN32)
     endif()
 else()
     set(CMAKE_POSITION_INDEPENDENT_CODE true)
-    set(JITTER_COMPILE_FLAGS "-DAWSLC -fwrapv --param ssp-buffer-size=4 -fvisibility=hidden -Wcast-align -Wmissing-field-initializers -Wshadow -Wswitch-enum -Wextra -Wall -pedantic -O0 -fwrapv")
+    set(JITTER_COMPILE_FLAGS "-DAWSLC -fwrapv --param ssp-buffer-size=4 -fvisibility=hidden -Wcast-align -Wmissing-field-initializers -Wshadow -Wswitch-enum -Wextra -Wall -pedantic -O0 -fwrapv -Wp,-U_FORTIFY_SOURCE")
     if ((NOT GCC) OR (GCC AND CMAKE_C_COMPILER_VERSION VERSION_GREATER "4.3"))
         # -Wconversion was changed from GCC version 4.3. Prior it was meant as
         # an aid in translating code from old C to modern C. It was not meant