diff --git a/CMakeLists.txt b/CMakeLists.txt
index 10952a010..a91e11da7 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -257,9 +257,14 @@ if(CMAKE_C_COMPILER_ID MATCHES "GNU" OR CMAKE_C_COMPILER_ID MATCHES "Clang")
   if(${CMAKE_BUILD_TYPE} STREQUAL "Debug")
     set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -g -O0 -DDEBUG_MODE")
   else(${CMAKE_BUILD_TYPE} STREQUAL "Debug")
-    set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -O3")
+    if(${CMAKE_BUILD_TYPE} STREQUAL "RelWithDebInfo")
+      set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -DDEBUG_MODE")
+    else(${CMAKE_BUILD_TYPE} STREQUAL "RelWithDebInfo")
+      set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -O3")
+    endif(${CMAKE_BUILD_TYPE} STREQUAL "RelWithDebInfo")
   endif(${CMAKE_BUILD_TYPE} STREQUAL "Debug")
 
+
   if (USE_LTE_RATES)
     message(STATUS "Using standard LTE sampling rates")
     set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -DFORCE_STANDARD_RATE")