diff --git a/gis/gdal/README b/gis/gdal/README
index 33a4894063..5103301463 100644
--- a/gis/gdal/README
+++ b/gis/gdal/README
@@ -9,7 +9,8 @@ The related OGR library (which is part of the GDAL source tree)
 provides a similar capability for simple features vector data.
 
 The following optional requirements are detected automatically:
-cfitsio, freexl, hdf, hdf5, libwebp, netcdf, postgresql, xerces-c
+cfitsio, freexl, hdf, hdf5, json-c, libwebp, netcdf, postgresql,
+xerces-c
 
 To enable OpenCL GPU-accelerated performance, specify the option
 OPENCL=yes (requires opencl-headers to build, and either nvidia-driver