diff --git a/lib/CMakeLists.txt b/lib/CMakeLists.txt
index a02a534b..4dc2fcdb 100644
--- a/lib/CMakeLists.txt
+++ b/lib/CMakeLists.txt
@@ -24,7 +24,6 @@ set(NGHTTP2_SOURCES
   nghttp2_http.c
   nghttp2_rcbuf.c
   nghttp2_debug.c
-  nghttp2_ksl.c
 )
 
 set(NGHTTP2_RES "")
diff --git a/lib/Makefile.msvc b/lib/Makefile.msvc
index ec96b542..f649c0bd 100644
--- a/lib/Makefile.msvc
+++ b/lib/Makefile.msvc
@@ -91,8 +91,7 @@ NGHTTP2_SRC := nghttp2_pq.c \
   nghttp2_callbacks.c \
   nghttp2_mem.c \
   nghttp2_http.c \
-  nghttp2_rcbuf.c \
-  nghttp2_ksl.c
+  nghttp2_rcbuf.c
 
 NGHTTP2_OBJ_R := $(addprefix $(OBJ_DIR)/r_, $(notdir $(NGHTTP2_SRC:.c=.obj)))
 NGHTTP2_OBJ_D := $(addprefix $(OBJ_DIR)/d_, $(notdir $(NGHTTP2_SRC:.c=.obj)))