diff --git a/gbl.spec b/gbl.spec
index b1499f03593..18120c98607 100644
--- a/gbl.spec
+++ b/gbl.spec
@@ -16,7 +16,7 @@ cd build
 
 cmake ../cpp \
   -DCMAKE_INSTALL_PREFIX=%{i} \
-  -DCMAKE_BUILD_TYPE=Release \
+  -DCMAKE_BUILD_TYPE=Debug \
   -DCMAKE_VERBOSE_MAKEFILE=ON \
   -DEIGEN3_INCLUDE_DIR=${EIGEN_ROOT}/include/eigen3 \
   -DSUPPORT_ROOT=False \