diff --git a/extern/CMakeLists.txt b/extern/CMakeLists.txt
index ac73e8a..5b0ecc3 100755
--- a/extern/CMakeLists.txt
+++ b/extern/CMakeLists.txt
@@ -18,15 +18,15 @@ FetchContent_Declare(
 FetchContent_Declare(
         spirv-cross
         GIT_REPOSITORY https://github.com/KhronosGroup/SPIRV-Cross.git
-        GIT_TAG MoltenVK-1.1.5
-        GIT_PROGRESS TRUE
+        GIT_TAG 0e2880ab990e79ce6cc8c79c219feda42d98b1e8
+        GIT_SHALLOW ON
 )
 
 FetchContent_Declare(
         glslang
         GIT_REPOSITORY https://github.com/KhronosGroup/glslang.git
         GIT_TAG df609a01b386001e367709086c58529c48028d1e # taken from https://github.com/KhronosGroup/SPIRV-Cross/blob/2021-01-15/checkout_glslang_spirv_tools.sh#L3
-        GIT_PROGRESS TRUE
+        GIT_SHALLOW ON
 )
 
 # bullet
@@ -72,10 +72,11 @@ add_subdirectory(magic_enum)
 add_subdirectory(smaa)
 add_subdirectory(doctest)
 
-FetchContent_Declare(json
+FetchContent_Declare(
+        json
         GIT_REPOSITORY https://github.com/ArthurSonzogni/nlohmann_json_cmake_fetchcontent.git
-        GIT_TAG v3.9.1
-        GIT_PROGRESS TRUE)
+        GIT_TAG 6aebf09233951e4ce30a63919186a70b2b195756
+        GIT_SHALLOW TRUE)
 
 FetchContent_GetProperties(json)
 if (NOT json_POPULATED)
@@ -117,8 +118,8 @@ endif ()
 FetchContent_Declare(
         fmt
         GIT_REPOSITORY https://github.com/fmtlib/fmt
-        GIT_TAG 8.0.1
-        GIT_PROGRESS TRUE
+        GIT_TAG b6f4ceaed0a0a24ccf575fab6c56dd50ccf6f1a9
+        GIT_SHALLOW TRUE
 )
 
 FetchContent_MakeAvailable(fmt)