diff --git a/libgeotiff/CMakeLists.txt b/libgeotiff/CMakeLists.txt
index 5e74c81..6b04c71 100644
--- a/libgeotiff/CMakeLists.txt
+++ b/libgeotiff/CMakeLists.txt
@@ -5,7 +5,7 @@
 # Author: Mateusz Loskot <mateusz@loskot.net>
 #
 ###############################################################################
-CMAKE_MINIMUM_REQUIRED(VERSION 3.13)
+CMAKE_MINIMUM_REQUIRED(VERSION 3.16...3.29)
 
 PROJECT(GeoTIFF)
 
diff --git a/libgeotiff/geo_normalize.c b/libgeotiff/geo_normalize.c
index a1d7f4b..525edb9 100644
--- a/libgeotiff/geo_normalize.c
+++ b/libgeotiff/geo_normalize.c
@@ -88,7 +88,10 @@
 #endif
 #endif
 
-CPL_INLINE static void CPL_IGNORE_RET_VAL_INT(CPL_UNUSED int unused) {}
+CPL_INLINE static void CPL_IGNORE_RET_VAL_INT(CPL_UNUSED int unused)
+{
+    (void)unused;
+}
 
 /************************************************************************/
 /*                          GTIFKeyGetSSHORT()                          */