diff --git a/external/external_build.cmake b/external/external_build.cmake
index 401abaf..2885053 100644
--- a/external/external_build.cmake
+++ b/external/external_build.cmake
@@ -234,6 +234,7 @@ ExternalProject_Add(cosmotool
 	-DGSLCBLAS_LIBRARY=${GSLCBLAS_LIBRARY}
 	-DNETCDF_LIBRARY=${NETCDF_LIBRARY}
 	-DNETCDFCPP_LIBRARY=${NETCDFCPP_LIBRARY}
+        -DENABLE_SHARP=OFF
 )
 SET(COSMOTOOL_LIBRARY ${CMAKE_BINARY_DIR}/ext_build/cosmotool/lib/libCosmoTool.a)
 set(COSMOTOOL_INCLUDE_PATH ${CMAKE_BINARY_DIR}/ext_build/cosmotool/include)