diff --git a/cmake/modules/CompileWarnings.cmake b/cmake/modules/CompileWarnings.cmake
index b9d1ab8..93b35b8 100644
--- a/cmake/modules/CompileWarnings.cmake
+++ b/cmake/modules/CompileWarnings.cmake
@@ -1,7 +1,15 @@
 macro(wpilib_target_warnings target)
     if(NOT MSVC)
-        target_compile_options(${target} PRIVATE -Wall -pedantic -Wextra -Werror -Wno-unused-parameter -Wno-error=deprecated-declarations ${WPILIB_TARGET_WARNINGS})
+        target_compile_options(${target} PRIVATE -Wall -pedantic -Wextra -Werror -Wno-unused-parameter ${WPILIB_TARGET_WARNINGS})
     else()
-        target_compile_options(${target} PRIVATE /wd4146 /wd4244 /wd4251 /wd4267 /wd4996 /WX ${WPILIB_TARGET_WARNINGS})
+        target_compile_options(${target} PRIVATE /wd4146 /wd4244 /wd4251 /wd4267 /WX /D_CRT_SECURE_NO_WARNINGS ${WPILIB_TARGET_WARNINGS})
+    endif()
+
+    # Suppress C++-specific OpenCV warning; C compiler rejects it with an error
+    # https://github.com/opencv/opencv/issues/20269
+    if(UNIX AND NOT APPLE)
+        target_compile_options(${target} PRIVATE $<$<COMPILE_LANGUAGE:CXX>:-Wno-deprecated-enum-enum-conversion>)
+    elseif(UNIX AND APPLE)
+        target_compile_options(${target} PRIVATE $<$<COMPILE_LANGUAGE:CXX>:-Wno-deprecated-anon-enum-enum-conversion>)
     endif()
 endmacro()