diff --git a/CMakeLists.txt b/CMakeLists.txt
index d869715..073a73f 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -117,10 +117,10 @@ endif()
 # On Windows GDI+ supports GIF, JPEG, EXIF, PNG, and TIFF.
 # see https://docs.microsoft.com/en-us/windows/desktop/gdiplus/-gdiplus-types-of-bitmaps-about
 if(SIMAGE_USE_GDIPLUS)
-  find_package(GdiPlus)
+  find_package(GdiPlus REQUIRED)
 endif()
 if(SIMAGE_USE_AVIENC)
-  find_package(Vfw)
+  find_package(Vfw REQUIRED)
 endif()
 
 # On macOS QuickTime supports BMP, GIF, JPEG, JPEG 2000, PNG, TIFF, and TGA.
@@ -267,7 +267,7 @@ if(SIMAGE_OGGVORBIS_SUPPORT)
   find_package(Ogg REQUIRED)
   find_package(Vorbis REQUIRED)
   if(OGG_FOUND)
-    find_package(Opus)
+    find_package(Opus REQUIRED)
   endif()
 endif()
 
@@ -287,8 +287,8 @@ if(NOT SIMAGE_QUICKTIME_SUPPORT AND NOT SIMAGE_CGIMAGE_SUPPORT AND NOT SIMAGE_GD
   if(SIMAGE_TIFF_SUPPORT)
     find_package(TIFF REQUIRED)
     if(TIFF_FOUND)
-      find_package(LibLZMA)
-      find_package(Zstd)
+      find_package(LibLZMA REQUIRED)
+      find_package(Zstd REQUIRED)
     endif()
   endif()