diff --git a/CMakeLists.txt b/CMakeLists.txt
index 287cd9b..17ba7b7 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -7,6 +7,7 @@ include(GNUInstallDirs)
 option(MATRIXSSL_BUILD_SHARED "Build MatrixSSL as a shared library" ON)
 option(MATRIXSSL_BUILD_STATIC "Build MatrixSSL as a static library" OFF)
 option(MATRIXSSL_DISABLE_TLS13 "Disable TLS 1.3 in the generated CMake configuration" ON)
+option(MATRIXSSL_BUILD_OPENSSL_COMPAT "Build MatrixSSL OpenSSL compatibility sources when this source tree provides them" OFF)
 set(MATRIXSSL_CONFIG "default" CACHE STRING "MatrixSSL configuration directory under configs/")
 set(MATRIXSSL_LIBRARY_PREFIX "" CACHE STRING "Prefix added to installed library output names, e.g. 'nw' for libnwmatrixssl")
 set(MATRIXSSL_INSTALL_INCLUDE_SUBDIR "matrixssl" CACHE STRING "Header install subdirectory below CMAKE_INSTALL_INCLUDEDIR")
@@ -192,6 +193,25 @@ set(MATRIXSSL_CRYPTO_SOURCES
     crypto/crypto_sign/ed25519/ref10/open.c
     crypto/crypto_sign/ps_ed25519.c)
 
+set(MATRIXSSL_OPENSSL_COMPAT_SOURCES
+    matrixssl/opensslApi.c
+    matrixssl/opensslSocket.c)
+
+set(MATRIXSSL_HAVE_OPENSSL_COMPAT TRUE)
+foreach(_matrixssl_compat_source IN LISTS MATRIXSSL_OPENSSL_COMPAT_SOURCES)
+    if(NOT EXISTS "${CMAKE_CURRENT_SOURCE_DIR}/${_matrixssl_compat_source}")
+        set(MATRIXSSL_HAVE_OPENSSL_COMPAT FALSE)
+    endif()
+endforeach()
+if(MATRIXSSL_BUILD_OPENSSL_COMPAT AND NOT MATRIXSSL_HAVE_OPENSSL_COMPAT)
+    message(FATAL_ERROR "MATRIXSSL_BUILD_OPENSSL_COMPAT=ON was requested, but this MatrixSSL source tree does not contain opensslApi.c/opensslSocket.c")
+endif()
+if(MATRIXSSL_HAVE_OPENSSL_COMPAT)
+    message(STATUS "MatrixSSL OpenSSL compatibility sources found")
+else()
+    message(STATUS "MatrixSSL OpenSSL compatibility sources not found; building native MatrixSSL API only")
+endif()
+
 set(MATRIXSSL_TLS_SOURCES
     matrixssl/matrixsslGetSet.c
     matrixssl/cipherSuite.c
@@ -247,6 +267,9 @@ set(MATRIXSSL_ALL_SOURCES
     ${MATRIXSSL_CORE_SOURCES}
     ${MATRIXSSL_CRYPTO_SOURCES}
     ${MATRIXSSL_TLS_SOURCES})
+if(MATRIXSSL_BUILD_OPENSSL_COMPAT AND MATRIXSSL_HAVE_OPENSSL_COMPAT)
+    list(APPEND MATRIXSSL_ALL_SOURCES ${MATRIXSSL_OPENSSL_COMPAT_SOURCES})
+endif()
 
 function(matrixssl_configure_target target_name)
     target_sources(${target_name} PRIVATE ${MATRIXSSL_ALL_SOURCES})
@@ -276,7 +299,9 @@ function(matrixssl_configure_target target_name)
         target_link_libraries(${target_name} PUBLIC pthread m)
     endif()
     set_target_properties(${target_name} PROPERTIES
-        OUTPUT_NAME "${MATRIXSSL_LIBRARY_PREFIX}matrixssl")
+        OUTPUT_NAME "${MATRIXSSL_LIBRARY_PREFIX}matrixssl"
+        VERSION "${PROJECT_VERSION}"
+        SOVERSION "${PROJECT_VERSION_MAJOR}")
 endfunction()
 
 if(MATRIXSSL_BUILD_SHARED)