diff --git a/CMakeLists.txt b/CMakeLists.txt
index 66d9ced4d..d949badb9 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -335,6 +335,8 @@ IF( NOT ZLIB_FOUND )
   SET(ZLIB_FOUND 1)
   SET(ZLIB_LIBRARIES zlibstatic)
   SET(ZLIB_INCLUDE_DIR ${CMAKE_CURRENT_SOURCE_DIR}/contrib/zlib ${CMAKE_CURRENT_BINARY_DIR}/contrib/zlib)
+  # need to ensure we don't link with system zlib or minizip as well.
+  SET(ASSIMP_BUILD_MINIZIP 1)
 ELSE(NOT ZLIB_FOUND)
   ADD_DEFINITIONS(-DASSIMP_BUILD_NO_OWN_ZLIB)
   SET(ZLIB_LIBRARIES_LINKED -lz)
@@ -343,10 +345,14 @@ INCLUDE_DIRECTORIES(${ZLIB_INCLUDE_DIR})
 
 # Search for unzip
 IF ( NOT IOS )
-	use_pkgconfig(UNZIP minizip)
+  IF( NOT ASSIMP_BUILD_MINIZIP )
+	  use_pkgconfig(UNZIP minizip)
+  ENDIF( NOT ASSIMP_BUILD_MINIZIP )
 ELSE ( NOT IOS )
 	IF(NOT BUILD_SHARED_LIBS)
-		use_pkgconfig(UNZIP minizip)
+    IF( NOT ASSIMP_BUILD_MINIZIP )
+		  use_pkgconfig(UNZIP minizip)
+    ENDIF( NOT ASSIMP_BUILD_MINIZIP )
 	ENDIF (NOT BUILD_SHARED_LIBS)
 ENDIF ( NOT IOS )