diff --git a/parallel-crypto3/CMakeLists.txt b/parallel-crypto3/CMakeLists.txt
index 916a540389..e4906392e2 100644
--- a/parallel-crypto3/CMakeLists.txt
+++ b/parallel-crypto3/CMakeLists.txt
@@ -3,6 +3,10 @@ project(parallel-crypto3)
 
 find_package(CM)
 
+if(${CMAKE_BUILD_TYPE} STREQUAL "Debug")
+    set(CMAKE_CXX_FLAGS "-ggdb -O0")
+endif()
+
 # This is useful due to some build systems (Ninja in particular) are piping
 # compiler output and compiler switches it's output to plain text
 option (FORCE_COLORED_OUTPUT "Always produce ANSI-colored output (GNU/Clang only)." FALSE)
diff --git a/parallel-crypto3/parallel-crypto3.nix b/parallel-crypto3/parallel-crypto3.nix
index adb78ca271..189efbc710 100644
--- a/parallel-crypto3/parallel-crypto3.nix
+++ b/parallel-crypto3/parallel-crypto3.nix
@@ -28,10 +28,7 @@ in stdenv.mkDerivation {
   cmakeFlags =
     [
       (if runTests then "-DBUILD_TESTS=TRUE" else "")
-      (if runTests then "-DCMAKE_ENABLE_TESTS=TRUE" else "")
       (if enableDebug then "-DCMAKE_BUILD_TYPE=Debug" else "-DCMAKE_BUILD_TYPE=Release")
-      (if enableDebug then "-DCMAKE_CXX_FLAGS=-ggdb" else "")
-      (if enableDebug then "-DCMAKE_CXX_FLAGS=-O0" else "")
     ];
 
   doCheck = runTests; # tests are inside crypto3-tests derivation