diff --git a/CMakeLists.txt b/CMakeLists.txt
index a9dd0385..5da6999a 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -194,7 +194,10 @@ endif()
 # openssl (for src)
 set(HAVE_OPENSSL    ${OPENSSL_FOUND})
 if(OPENSSL_FOUND)
-  set(OPENSSL_INCLUDE_DIRS ${OPENSSL_INCLUDE_DIR})
+  set(OPENSSL_INCLUDE_DIRS  ${OPENSSL_INCLUDE_DIR})
+else()
+  set(OPENSSL_INCLUDE_DIRS  "")
+  set(OPENSSL_LIBRARIES     "")
 endif()
 # libev (for src)
 set(HAVE_LIBEV      ${LIBEV_FOUND})
@@ -208,6 +211,12 @@ endif()
 set(HAVE_JANSSON    ${JANSSON_FOUND})
 # libxml2 (for src/nghttp)
 set(HAVE_LIBXML2    ${LIBXML2_FOUND})
+if(LIBXML2_FOUND)
+  set(LIBXML2_INCLUDE_DIRS  ${LIBXML2_INCLUDE_DIR})
+else()
+  set(LIBXML2_INCLUDE_DIRS  "")
+  set(LIBXML2_LIBRARIES     "")
+endif()
 # jemalloc
 set(HAVE_JEMALLOC   ${JEMALLOC_FOUND})
 # spdylay (for src/nghttpx and src/h2load)
diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index 3caf0edc..e5b99d8c 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -16,7 +16,7 @@ include_directories(
 
   ${JEMALLOC_INCLUDE_DIRS}
   ${SPDYLAY_INCLUDE_DIRS}
-  ${LIBXML2_INCLUDE_DIR}
+  ${LIBXML2_INCLUDE_DIRS}
   ${LIBEV_INCLUDE_DIRS}
   ${OPENSSL_INCLUDE_DIRS}
   ${JANSSON_INCLUDE_DIRS}