--- a/external/CMakeLists.txt	2026-10-01 08:53:51.315815599 +0200
+++ b/external/CMakeLists.txt	2026-10-01 08:53:46.253074200 +0200
@@ -1,4 +1,4 @@
-add_library(cjson cJSON/src/cJSON.c)
+add_library(cjson STATIC cJSON/src/cJSON.c)
 add_library(External::cjson ALIAS cjson)
 target_include_directories(cjson
     PUBLIC ${CMAKE_CURRENT_SOURCE_DIR}/cJSON/include
@@ -6,7 +6,7 @@
 )
 rt_setup_target(cjson)
 
-add_library(jpeg_ijg jpeg_ijg/src/jdatasrc.cc jpeg_ijg/src/jpeg_memsrc.cc)
+add_library(jpeg_ijg STATIC jpeg_ijg/src/jdatasrc.cc jpeg_ijg/src/jpeg_memsrc.cc)
 add_library(External::jpeg_ijg ALIAS jpeg_ijg)
 target_include_directories(jpeg_ijg
     PUBLIC ${CMAKE_CURRENT_SOURCE_DIR}/jpeg_ijg/include
@@ -16,7 +16,7 @@
 rt_setup_target(jpeg_ijg)
 
 if(NOT WITH_SYSTEM_KLT)
-    add_library(klt
+    add_library(klt STATIC
         klt/src/convolve.cc
         klt/src/error.cc
         klt/src/klt_util.cc