diff --git a/Linux/build_openssl.sh b/Linux/build_openssl.sh
index 9481ac9e..59648656 100755
--- a/Linux/build_openssl.sh
+++ b/Linux/build_openssl.sh
@@ -37,10 +37,10 @@
 SGXSSL_ROOT="$( cd "$( dirname "${BASH_SOURCE[0]}" )" && pwd )"
 echo $SGXSSL_ROOT
 
-OPENSSL_VERSION=`ls $SGXSSL_ROOT/../openssl_source/*1.1.1*.tar.gz | head -1 | grep -o '[^/]*$' | sed -s -- 's/\.tar\.gz//'`
+OPENSSL_VERSION=`ls $SGXSSL_ROOT/../openssl_source/*1.1.1q.tar.gz | head -1 | grep -o '[^/]*$' | sed -s -- 's/\.tar\.gz//'`
 if [ "$OPENSSL_VERSION" == "" ] 
 then
-	echo "In order to run this script, OpenSSL tar.gz package must be located in openssl_source/ directory."
+	echo "In order to run this script, OpenSSL 1.1.1q tar.gz package must be located in openssl_source/ directory."
 	exit 1
 fi
 echo $OPENSSL_VERSION
diff --git a/README.md b/README.md
index d219e41e..9c0836d3 100644
--- a/README.md
+++ b/README.md
@@ -5,7 +5,7 @@ Introduction
 ------------
 The Intel® Software Guard Extensions SSL (Intel® SGX SSL) cryptographic library is intended to provide cryptographic services for Intel® Software Guard Extensions (SGX) enclave applications.
 The Intel® SGX SSL cryptographic library is based on the underlying OpenSSL* Open Source project, providing a full-strength general purpose cryptography library.
-Supported OpenSSL version is 1.1.1p. To work with 1.1.0 version please use "openssl_1.1.0" branch.
+Supported OpenSSL version is 1.1.1q. To work with 1.1.0 version please use "openssl_1.1.0" branch.
 
 In order to build Intel® SGX SSL libraries based on old OpenSSL version, checkout the tag with the corresponding versioning, e.g. lin_2.5_1.1.1c. Tag naming convention ``[lin/win]_<Intel(R) SGX SDK VERSION>_<OpenSSL VERSION>``.
 
@@ -35,11 +35,11 @@ Windows
  (Note: Perl, NASM need to be included in machine's PATH variable)
 
 To build Intel® SGX SSL package in Windows OS:
-1. Download OpenSSL package into openssl_source/ directory. (tar.gz package, e.g. openssl-1.1.1p.tar.gz)
+1. Download OpenSSL package into openssl_source/ directory. (tar.gz package, e.g. openssl-1.1.1q.tar.gz)
 2. Download and install latest SGX SDK from [Intel Developer Zone](https://software.intel.com/en-us/sgx-sdk/download). You can find installation guide from the same website.
 3. Change the directory to the SGXSSL path and enter the following command:
 ```
-build_all.cmd <OPENSSL_VERSION> [default == openssl-1.1.1]
+build_all.cmd
 ```
 This will build the Intel® SGX SSL libraries (libsgx_tsgxssl.lib, libsgx_usgxssl.lib, libsgx_tsgxssl_crypto.lib), which can be found in package/lib/{Win32|X64}/{debug|release}/. And the version with CVE-2020-0551 Mitigation enabled can be found in package/lib/X64/{CVE-2020-0551-CF-Release|CVE-2020-0551-Load-Release}/.
 
@@ -51,7 +51,7 @@ Linux
 - Intel(R) SGX Linux latest release, including SDK, PSW, and driver
 
 To build Intel® SGX SSL package in Linux OS:
-1. Download OpenSSL 1.1.1p package into openssl_source/ directory. (tar.gz package, e.g. openssl-1.1.1p.tar.gz)
+1. Download OpenSSL 1.1.1q package into openssl_source/ directory. (tar.gz package, e.g. openssl-1.1.1q.tar.gz)
 2. Download and install latest SGX SDK from [01.org](https://01.org/intel-software-guard-extensions/downloads). You can find installation guide in the same website.
 3. Source SGX SDK's environment variables.
 4. Cd to Linux/ directory and run:
diff --git a/Windows/build_all.cmd b/Windows/build_all.cmd
index c476a948..6fc2b918 100644
--- a/Windows/build_all.cmd
+++ b/Windows/build_all.cmd
@@ -36,7 +36,7 @@ Rem
 set SGXSSL_VERSION=1.9.100.%errorlevel%
 
 REM Check if Prerequisites apps available
-echo "Validating Prerequisites (perl, nasm)"
+echo "Validating Prerequisites (Perl, NASM, OpenSSL source)"
 perl -v > nul 2>&1
 if %errorlevel% neq 0 (
 	echo "Build failed, can't find perl."
@@ -48,12 +48,11 @@ if %errorlevel% neq 0 (
 	exit /b 1
 )
 
+set OPENSSL_VERSION=openssl-1.1.1q
 
-REM This variable must be set to the openssl file name (version) located in the openssl_source folder
-if "%1"=="" (
-	set OPENSSL_VERSION=openssl-1.1.1
-) else (
-	set OPENSSL_VERSION=%1
+if not exist ..\openssl_source\%OPENSSL_VERSION%.tar.gz (
+        echo "Please download %OPENSSL_VERSION%.tar.gz and put at ..\openssl_source\"
+	exit /b 1
 )
 
 for /f "tokens=2*" %%A in ('REG QUERY "HKLM\SOFTWARE\Intel\SGX_PSW" /v Version') DO (