diff --git a/CMakeLists.txt b/CMakeLists.txt
index fc2d146..ec97e26 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -1,4 +1,5 @@
-cmake_minimum_required (VERSION 3.0)
+# Ubuntu 18.04 LTS and OpenBSD 6.4
+cmake_minimum_required (VERSION 3.10)
 project (uirc3 VERSION 1.4.0 LANGUAGES C)
 
 # Options
@@ -6,10 +7,13 @@ option (WANT_READLINE "Use GNU Readline for the UI (better)" ON)
 option (WANT_LIBEDIT "Use BSD libedit for the UI" OFF)
 
 # Moar warnings
+set (CMAKE_C_STANDARD 99)
+set (CMAKE_C_STANDARD_REQUIRED ON)
+set (CMAKE_C_EXTENSIONS OFF)
+
 if ("${CMAKE_C_COMPILER_ID}" MATCHES "GNU" OR CMAKE_COMPILER_IS_GNUCC)
 	# -Wunused-function is pretty annoying here, as everything is static
-	set (wdisabled "-Wno-unused-function")
-	set (CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -std=c99 -Wall -Wextra ${wdisabled}")
+	set (CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Wall -Wextra -Wno-unused-function")
 endif ()
 
 # Version