diff --git a/CMakeLists.txt b/CMakeLists.txt
index 787fb1b07d..409a1b52dc 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -33,7 +33,7 @@ endif()
 option(openmp   "Enable shared-memory parallelism with OpenMP"   ON)
 option(profile  "Compile with profiling flags"                   OFF)
 option(debug    "Compile with debug flags"                       OFF)
-option(optimize "Turn on all compiler optimization flags"        ON)
+option(optimize "Turn on all compiler optimization flags"        OFF)
 option(coverage "Compile with coverage analysis flags"           OFF)
 option(mpif08   "Use Fortran 2008 MPI interface"                 OFF)