diff --git a/Modules/ExternalProject.cmake b/Modules/ExternalProject.cmake
index 3de6b7e68..390b8f923 100644
--- a/Modules/ExternalProject.cmake
+++ b/Modules/ExternalProject.cmake
@@ -403,11 +403,11 @@ endfunction(_ep_write_verifyfile_script)
 function(_ep_write_extractfile_script script_filename name filename directory)
   set(args "")
 
-  if(filename MATCHES "(\\.bz2|\\.tar\\.gz|\\.tgz|\\.zip)$")
+  if(filename MATCHES "(\\.|=)(bz2|tar\\.gz|tgz|zip)$")
     set(args xfz)
   endif()
 
-  if(filename MATCHES "\\.tar$")
+  if(filename MATCHES "(\\.|=)tar$")
     set(args xf)
   endif()
 
@@ -1109,10 +1109,15 @@ function(_ep_add_download_command name)
     else()
       if("${url}" MATCHES "^[a-z]+://")
         # TODO: Should download and extraction be different steps?
-        string(REGEX MATCH "[^/]*$" fname "${url}")
-        if(NOT "${fname}" MATCHES "\\.(bz2|tar|tgz|tar\\.gz|zip)$")
+        string(REGEX MATCH "[^/\\?]*$" fname "${url}")
+        if(NOT "${fname}" MATCHES "(\\.|=)(bz2|tar|tgz|tar\\.gz|zip)$")
+          string(REGEX MATCH "([^/\\?]+(\\.|=)(bz2|tar|tgz|tar\\.gz|zip))/.*$" match_result "${url}")
+          set(fname "${CMAKE_MATCH_1}")
+        endif()
+        if(NOT "${fname}" MATCHES "(\\.|=)(bz2|tar|tgz|tar\\.gz|zip)$")
           message(FATAL_ERROR "Could not extract tarball filename from url:\n  ${url}")
         endif()
+        string(REPLACE ";" "-" fname "${fname}")
         set(file ${download_dir}/${fname})
         get_property(timeout TARGET ${name} PROPERTY _EP_TIMEOUT)
         _ep_write_downloadfile_script("${stamp_dir}/download-${name}.cmake" "${url}" "${file}" "${timeout}" "${md5}")