diff --git a/README.md b/README.md
index d21a517..31f8ddf 100644
--- a/README.md
+++ b/README.md
@@ -6,6 +6,8 @@ Original nim LevelDB wrapper: [HERE](https://github.com/zielmicha/leveldb.nim)
 
 Replacing of system library dependency with self-contained C/CPP interoperability by (Codex.Storage)[https://codex.storage]
 
+## Usage
+
 Create a database:
 ```Nim
    import leveldbstatic
@@ -49,3 +51,13 @@ Iterate over subset of database content:
 
    db.close()
 ```
+
+## Compiling with optimizations
+
+This library can be compiled with the following optimization options. By default these are disabled. Provide the following nim compiler flags to enable them:
+ - fdatasync from <unistd.h> `--passC:-DHAVE_FDATASYNC=1`
+ - F_FULLSYNC from <fcntl.h> `--passC:-DHAVE_FULLFSYNC=1`
+ - O_CLOEXEC from <fcntl.h> `--passC:-DHAVE_O_CLOEXEC=1`
+ - crc32c from <crc32c/crc32c.h> `--passC:-DHAVE_CRC32C=1`
+ - snappy from <snappy.h> `--passC:-DHAVE_SNAPPY=1`
+ - zstd from <zstd.h> `--passC:-DHAVE_ZSTD=1`
diff --git a/build.sh b/build.sh
index 55bbe9c..dd683df 100755
--- a/build.sh
+++ b/build.sh
@@ -47,10 +47,9 @@ toast \
   --includeDirs="${sourceDir}/helpers/memenv" \
   --includeDirs="${sourceDir}/port" \
   --includeDirs="${sourceDir}/include" \
-  --includeDirs="${buildDir}/include" \
+  --includeDirs="${root}/leveldbstatic/include" \
   "${sourceDir}/include/leveldb/c.h" >> "${output}"
 
 sed -i 's/\bpassC\b/passc/g' "${output}"
 sed -i 's/{\.compile\:\ \"\./{\.compile\:\ root\ \&\ \"/g' "${output}"
 sed -i 's/{\.passc\:\ \"-I\./{\.passc\:\ \"-I\"\ \&\ root\ \&\ \"/g' "${output}"
-
diff --git a/build/.keep b/build/.keep
new file mode 100644
index 0000000..e69de29
diff --git a/checkers/check_crc32c.c b/checkers/check_crc32c.c
deleted file mode 100644
index 4eca8f1..0000000
--- a/checkers/check_crc32c.c
+++ /dev/null
@@ -1,9 +0,0 @@
-#include <crc32c/crc32c.h>
-
-int main(int argc, char** argv)
-{
-  char* buffer;
-  size_t size;
-  ::crc32c::Extend(0, buffer, size);
-  return 0;
-}
diff --git a/checkers/check_fdatasync.c b/checkers/check_fdatasync.c
deleted file mode 100644
index 63d1ed1..0000000
--- a/checkers/check_fdatasync.c
+++ /dev/null
@@ -1,7 +0,0 @@
-#include <unistd.h>
-
-int main(int argc, char** argv)
-{
-  fdatasync(-1);
-  return 0;
-}
diff --git a/checkers/check_fullfsync.c b/checkers/check_fullfsync.c
deleted file mode 100644
index 7632eed..0000000
--- a/checkers/check_fullfsync.c
+++ /dev/null
@@ -1,7 +0,0 @@
-#include <fcntl.h>
-
-int main(int argc, char** argv)
-{
-  int i = F_FULLSYNC;
-  return 0;
-}
diff --git a/checkers/check_ocloexec.c b/checkers/check_ocloexec.c
deleted file mode 100644
index c719871..0000000
--- a/checkers/check_ocloexec.c
+++ /dev/null
@@ -1,7 +0,0 @@
-#include <fcntl.h>
-
-int main(int argc, char** argv)
-{
-  int i = O_CLOEXEC;
-  return 0;
-}
diff --git a/checkers/check_snappy.c b/checkers/check_snappy.c
deleted file mode 100644
index 21b8111..0000000
--- a/checkers/check_snappy.c
+++ /dev/null
@@ -1,10 +0,0 @@
-#include <snappy.h>
-
-int main(int argc, char** argv)
-{
-  char* input;
-  size_t length;
-  size_t result;
-  snappy::GetUncompressedLength(input, length, &result);
-  return 0;
-}
diff --git a/checkers/check_zstd.c b/checkers/check_zstd.c
deleted file mode 100644
index 837cdb0..0000000
--- a/checkers/check_zstd.c
+++ /dev/null
@@ -1,8 +0,0 @@
-#include <zstd.h>
-
-int main(int argc, char** argv)
-{
-  size_t length;
-  ZSTD_compressBound(length);
-  return 0;
-}
diff --git a/build/include/port/port_config.h b/leveldbstatic/include/port/port_config.h
similarity index 93%
rename from build/include/port/port_config.h
rename to leveldbstatic/include/port/port_config.h
index 0e80eda..a1b8c7a 100644
--- a/build/include/port/port_config.h
+++ b/leveldbstatic/include/port/port_config.h
@@ -7,7 +7,7 @@
 
 // Define to 1 if you have a definition for fdatasync() in <unistd.h>.
 #if !defined(HAVE_FDATASYNC)
-#define HAVE_FDATASYNC 1
+#define HAVE_FDATASYNC 0
 #endif  // !defined(HAVE_FDATASYNC)
 
 // Define to 1 if you have a definition for F_FULLFSYNC in <fcntl.h>.
@@ -17,7 +17,7 @@
 
 // Define to 1 if you have a definition for O_CLOEXEC in <fcntl.h>.
 #if !defined(HAVE_O_CLOEXEC)
-#define HAVE_O_CLOEXEC 1
+#define HAVE_O_CLOEXEC 0
 #endif  // !defined(HAVE_O_CLOEXEC)
 
 // Define to 1 if you have Google CRC32C.
@@ -31,7 +31,7 @@
 #endif  // !defined(HAVE_SNAPPY)
 
 // Define to 1 if you have Zstd.
-#if !defined(HAVE_Zstd)
+#if !defined(HAVE_ZSTD)
 #define HAVE_ZSTD 0
 #endif  // !defined(HAVE_ZSTD)
 
diff --git a/leveldbstatic/prelude.nim b/leveldbstatic/prelude.nim
index 377685c..b000f9c 100644
--- a/leveldbstatic/prelude.nim
+++ b/leveldbstatic/prelude.nim
@@ -3,7 +3,6 @@ import os
 const root = currentSourcePath.parentDir.parentDir
 const envWindows = root/"vendor"/"util"/"env_windows.cc"
 const envPosix = root/"vendor"/"util"/"env_posix.cc"
-const checkers = root/"checkers"
 
 when defined(windows):
   {.compile: envWindows.}
@@ -14,20 +13,3 @@ when defined(windows):
 when defined(posix):
   {.compile: envPosix.}
   {.passc: "-DLEVELDB_PLATFORM_POSIX".}
-
-
-static:
-  proc doesCompile(cfile: string): int =
-    let rv = gorgeEx("gcc " & cfile)
-    if rv[1] == 0:
-      return 1
-    return 0
-
-  {.passc: "-DHAVE_FDATASYNC=" & $doesCompile(checkers/"check_fdatasync.c").}
-  {.passc: "-DHAVE_FULLFSYNC=" & $doesCompile(checkers/"check_fullfsync.c").}
-  {.passc: "-DHAVE_O_CLOEXEC=" & $doesCompile(checkers/"check_ocloexec.c").}
-  {.passc: "-DHAVE_CRC32C=" & $doesCompile(checkers/"check_crc32c.c").}
-  {.passc: "-DHAVE_SNAPPY=" & $doesCompile(checkers/"check_snappy.c").}
-  {.passc: "-DHAVE_ZSTD=" & $doesCompile(checkers/"check_zstd.c").}
-  {.passc: "-DHAVE_Zstd=" & $doesCompile(checkers/"check_zstd.c").}
-