Prevent WIN32 libraries being used on linux
diff --git a/src/cmake/FindAPR.cmake b/src/cmake/FindAPR.cmake
index 73876c4..8118ff7 100644
--- a/src/cmake/FindAPR.cmake
+++ b/src/cmake/FindAPR.cmake
@@ -45,7 +45,11 @@
 else()
     find_path(APR_INCLUDE_DIR apr.h PATH_SUFFIXES apr-1)
     if (APR_STATIC OR NOT BUILD_SHARED_LIBS)
-      set(APR_SYSTEM_LIBS  ws2_32  mswsock  rpcrt4)
+      if(WIN32)
+        set(APR_SYSTEM_LIBS  ws2_32  mswsock  rpcrt4)
+      else()
+        set(APR_SYSTEM_LIBS  pthread)
+      endif()
       set(APR_COMPILE_DEFINITIONS APR_DECLARE_STATIC)
       find_library(APR_LIBRARIES NAMES apr-1)
     else()