diff --git a/doxygen/CMakeLists.txt b/doxygen/CMakeLists.txt
index 6a0323f..4f18087 100644
--- a/doxygen/CMakeLists.txt
+++ b/doxygen/CMakeLists.txt
@@ -32,9 +32,9 @@ IF(DCMTK_WITH_DOXYGEN)
   ENDIF(NOT WIN32)
 
   # install html docs and manpages
-  INSTALL(DIRECTORY ${CMAKE_CURRENT_BINARY_DIR}/htmldocs/ DESTINATION ${CMAKE_INSTALL_PREFIX}${INSTALL_HTMDIR} PATTERN "CVS" EXCLUDE)
+  INSTALL(DIRECTORY ${CMAKE_CURRENT_BINARY_DIR}/htmldocs/ DESTINATION ${INSTALL_HTMDIR} PATTERN "CVS" EXCLUDE)
   IF(NOT WIN32)
-    INSTALL(DIRECTORY ${CMAKE_CURRENT_BINARY_DIR}/manpages/ DESTINATION ${CMAKE_INSTALL_PREFIX}${INSTALL_MANDIR} PATTERN "CVS" EXCLUDE)
+    INSTALL(DIRECTORY ${CMAKE_CURRENT_BINARY_DIR}/manpages/ DESTINATION ${INSTALL_MANDIR} PATTERN "CVS" EXCLUDE)
   ENDIF(NOT WIN32)
 
   # cleanup created files on "make clean" - directories are not removed with CMake 2.4 :-/