diff --git a/CompilerChecks.cmake b/CompilerChecks.cmake
index 7a25b592..81fb5462 100644
--- a/CompilerChecks.cmake
+++ b/CompilerChecks.cmake
@@ -16,7 +16,6 @@ if (UNIX)
         endif()
     endif()
 
-    add_c_compiler_flag("-std=gnu99" SUPPORTED_COMPILER_FLAGS)
     add_c_compiler_flag("-Wpedantic" SUPPORTED_COMPILER_FLAGS)
     add_c_compiler_flag("-Wall" SUPPORTED_COMPILER_FLAGS)
     add_c_compiler_flag("-Wshadow" SUPPORTED_COMPILER_FLAGS)
diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index 93ecb5e7..199acbd9 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -355,6 +355,8 @@ endif (WITH_SYMBOL_VERSIONING AND HAVE_LD_VERSION_SCRIPT)
 
 set_target_properties(ssh
     PROPERTIES
+      C_STANDARD
+        99
       VERSION
         ${LIBRARY_VERSION}
       SOVERSION