diff --git a/pkgs/development/libraries/composable_kernel/default.nix b/pkgs/development/libraries/composable_kernel/default.nix
index 882aa1a918d9..8ce90c5f0ae5 100644
--- a/pkgs/development/libraries/composable_kernel/default.nix
+++ b/pkgs/development/libraries/composable_kernel/default.nix
@@ -8,7 +8,7 @@
 , gtest ? null
 , buildTests ? false
 , buildExamples ? false
-, gpuTargets ? null # gpuTargets = [ "gfx803" "gfx900" "gfx1030" ... ]
+, gpuTargets ? [ ] # gpuTargets = [ "gfx803" "gfx900" "gfx1030" ... ]
 }:
 
 assert buildTests -> gtest != null;
@@ -54,7 +54,7 @@ stdenv.mkDerivation (finalAttrs: {
   cmakeFlags = [
     "-DCMAKE_C_COMPILER=hipcc"
     "-DCMAKE_CXX_COMPILER=hipcc"
-  ] ++ lib.optionals (gpuTargets != null) [
+  ] ++ lib.optionals (gpuTargets != [ ]) [
     "-DGPU_TARGETS=${lib.strings.concatStringsSep ";" gpuTargets}"
   ];
 
diff --git a/pkgs/development/libraries/rocwmma/default.nix b/pkgs/development/libraries/rocwmma/default.nix
index a2312f73654b..8e66f9cf1327 100644
--- a/pkgs/development/libraries/rocwmma/default.nix
+++ b/pkgs/development/libraries/rocwmma/default.nix
@@ -15,7 +15,7 @@
 , buildDocs ? true
 , buildTests ? false
 , buildSamples ? false
-, gpuTargets ? null # gpuTargets = [ "gfx908:xnack-" "gfx90a:xnack-" "gfx90a:xnack+" ... ]
+, gpuTargets ? [ ] # gpuTargets = [ "gfx908:xnack-" "gfx90a:xnack-" "gfx90a:xnack+" ... ]
 }:
 
 assert buildTests -> gtest != null;
@@ -98,7 +98,7 @@ in stdenv.mkDerivation (finalAttrs: {
     "-DCMAKE_INSTALL_BINDIR=bin"
     "-DCMAKE_INSTALL_LIBDIR=lib"
     "-DCMAKE_INSTALL_INCLUDEDIR=include"
-  ] ++ lib.optionals (gpuTargets != null) [
+  ] ++ lib.optionals (gpuTargets != [ ]) [
     "-DGPU_TARGETS=${lib.strings.concatStringsSep ";" gpuTargets}"
   ] ++ lib.optionals buildTests [
     "-DROCWMMA_BUILD_VALIDATION_TESTS=ON"