diff -rup a/ogr/ogrct.cpp b/ogr/ogrct.cpp
--- a/ogr/ogrct.cpp	2018-05-04 18:08:49.000000000 +0200
+++ b/ogr/ogrct.cpp	2018-05-14 09:49:42.824062814 +0200
@@ -125,6 +125,7 @@ static bool      bProjLocaleSafe = false
 #  define LIBNAME "libproj.dylib"
 #else
 #  define LIBNAME "libproj.so"
+#  define LIBNAME "libproj.so.12"
 #endif
 
 #endif // PROJ_VERSION == 4