diff --git a/src/external/e57.cmake b/src/external/e57.cmake
index 0ed03da8c..441ab13a2 100644
--- a/src/external/e57.cmake
+++ b/src/external/e57.cmake
@@ -30,12 +30,13 @@ if (TARGET XercesC::XercesC)
 			message(STATUS "- libE57 - using downloaded source")
 
 			set(MESSAGE_QUIET ON)
+			set(E57_BUILD_SHARED OFF)
 			add_subdirectory(${LIBE57_DIR} EXCLUDE_FROM_ALL)
 			unset(MESSAGE_QUIET)
 
 			add_library(external-libE57 INTERFACE)
 			target_link_libraries(external-libE57 INTERFACE E57Format)
-			install(TARGETS E57Format DESTINATION ${MESHLAB_LIB_INSTALL_DIR})
+			#install(TARGETS E57Format DESTINATION ${MESHLAB_LIB_INSTALL_DIR})
 		endif()
 	endif()
 else()
diff --git a/src/external/lib3ds.cmake b/src/external/lib3ds.cmake
index 0dde58b17..4c53e9c5f 100644
--- a/src/external/lib3ds.cmake
+++ b/src/external/lib3ds.cmake
@@ -34,7 +34,7 @@ elseif(MESHLAB_ALLOW_DOWNLOAD_SOURCE_LIB3DS)
 	if (EXISTS ${LIB3DS_CHECK})
 		message(STATUS "- lib3ds - using downloaded source")
 		add_library(
-			external-lib3ds SHARED
+			external-lib3ds STATIC
 			"${LIB3DS_DIR}/lib3ds/atmosphere.c"
 			"${LIB3DS_DIR}/lib3ds/atmosphere.h"
 			"${LIB3DS_DIR}/lib3ds/background.c"
@@ -76,6 +76,6 @@ elseif(MESHLAB_ALLOW_DOWNLOAD_SOURCE_LIB3DS)
 
 		target_include_directories(external-lib3ds SYSTEM PUBLIC "${LIB3DS_DIR}")
 		target_link_libraries(external-lib3ds PRIVATE external-disable-warnings)
-		install(TARGETS external-lib3ds DESTINATION ${MESHLAB_LIB_INSTALL_DIR})
+		#install(TARGETS external-lib3ds DESTINATION ${MESHLAB_LIB_INSTALL_DIR})
 	endif()
 endif()
diff --git a/src/external/muparser.cmake b/src/external/muparser.cmake
index d13f50bd4..6640a37ae 100644
--- a/src/external/muparser.cmake
+++ b/src/external/muparser.cmake
@@ -38,6 +38,7 @@ elseif(MESHLAB_ALLOW_DOWNLOAD_SOURCE_MUPARSER)
 		if(NOT OpenMP_CXX_FOUND)
 			set(ENABLE_OPENMP OFF)
 		endif()
+		set(BUILD_SHARED_LIBS OFF)
 		add_subdirectory(${MUPARSER_DIR} EXCLUDE_FROM_ALL)
 		if (APPLE AND OpenMP_CXX_FOUND)
 			target_link_libraries(muparser PRIVATE OpenMP::OpenMP_CXX)
@@ -51,6 +52,6 @@ elseif(MESHLAB_ALLOW_DOWNLOAD_SOURCE_MUPARSER)
 
 		add_library(external-muparser INTERFACE)
 		target_link_libraries(external-muparser INTERFACE muparser)
-		install(TARGETS muparser DESTINATION ${MESHLAB_LIB_INSTALL_DIR})
+		#install(TARGETS muparser DESTINATION ${MESHLAB_LIB_INSTALL_DIR})
 	endif()
 endif()
diff --git a/src/external/u3d.cmake b/src/external/u3d.cmake
index a6305c0df..bba000f4c 100644
--- a/src/external/u3d.cmake
+++ b/src/external/u3d.cmake
@@ -28,7 +28,7 @@ if(MESHLAB_ALLOW_DOWNLOAD_SOURCE_U3D)
 
 		set(U3D_BUILD_LIBIDTF_TEST OFF)
 		set(U3D_BUILD_IDTF_TO_U3D_BIN OFF)
-		set(U3D_BUILD_STATIC_IDTF_LIB OFF)
+		set(U3D_BUILD_STATIC_IDTF_LIB ON)
 		set(U3D_INSTALL_LIBS OFF)
 		set(MESSAGE_QUIET ON)
 		add_subdirectory(${U3D_DIR})