diff --git a/projects/CMakeLists.txt b/projects/CMakeLists.txt
index 633de066b15844e842117264075dc6cdfb2bfc12..b622c2ad26f5c7a92a4e55323452dd82776c1e7d 100644
--- a/projects/CMakeLists.txt
+++ b/projects/CMakeLists.txt
@@ -187,7 +187,7 @@ LCGPackage_Add(
              -DGCCXML=${GCCXML_home}/bin/gccxml
              -DCLHEP_ROOT_DIR=${CLHEP_home}
              -DHEPMC_ROOT_DIR=${HepMC_home}
-	     -DGSL_ROOT_DIR=${GSL_home}
+             -DGSL_ROOT_DIR=${GSL_home}
              -DHEPPDT_ROOT_DIR=${HepPDT_home}
   BUILD_COMMAND ${MAKE} ROOTSYS=${ROOT_home}
   DEPENDS cmaketools ROOT GCCXML CLHEP HepMC HepPDT GSL