diff --git a/libtiledbsoma/CMakeLists.txt b/libtiledbsoma/CMakeLists.txt
index a055d71cd2..ad2bd803ca 100644
--- a/libtiledbsoma/CMakeLists.txt
+++ b/libtiledbsoma/CMakeLists.txt
@@ -91,6 +91,8 @@ endif()
 if(APPLE)
   set(CMAKE_MACOSX_RPATH ON)
 
+  set(CMAKE_OSX_DEPLOYMENT_TARGET 10.15)
+
   # Don't allow macOS .frameworks to be used for dependencies.
   set(CMAKE_FIND_FRAMEWORK NEVER)
 endif()