diff --git a/.appveyor/install.bat b/.appveyor/install.bat
index 1e2e5e0b8c..c45fef4b84 100644
--- a/.appveyor/install.bat
+++ b/.appveyor/install.bat
@@ -34,6 +34,8 @@ GOTO:EOF
     call:logInfo "Setup GYP/Ninja and generate VS solution"
     cd %LIB_DIR%
     git clone https://chromium.googlesource.com/external/gyp
+    cd gyp
+    git checkout a478c1ab51
     SET PATH=%PATH%;C:\TBuild\Libraries\gyp;C:\TBuild\Libraries\ninja;
     cd %SRC_DIR%
     git submodule init
diff --git a/Telegram/SourceFiles/codegen/scheme/codegen_scheme.py b/Telegram/SourceFiles/codegen/scheme/codegen_scheme.py
index 89ad9bcab4..b559c15f26 100644
--- a/Telegram/SourceFiles/codegen/scheme/codegen_scheme.py
+++ b/Telegram/SourceFiles/codegen/scheme/codegen_scheme.py
@@ -22,8 +22,14 @@ import glob, re, binascii, os, sys
 
 input_file = ''
 output_path = ''
+next_output_path = False
 for arg in sys.argv[1:]:
-  if re.match(r'^-o(.+)', arg):
+  if next_output_path:
+    next_output_path = False
+    output_path = arg
+  elif arg == '-o':
+    next_output_path = True
+  elif re.match(r'^-o(.+)', arg):
     output_path = arg[2:]
   else:
     input_file = arg
diff --git a/Telegram/gyp/codegen_rules.gypi b/Telegram/gyp/codegen_rules.gypi
index bbdca962f3..b52a91bb9d 100644
--- a/Telegram/gyp/codegen_rules.gypi
+++ b/Telegram/gyp/codegen_rules.gypi
@@ -29,8 +29,8 @@
     ],
     'action': [
       'python', '<(DEPTH)/update_dependent.py', '--styles',
-      '-I<(res_loc)', '-I<(src_loc)',
-      '-o<(SHARED_INTERMEDIATE_DIR)/update_dependent_styles.timestamp',
+      '-I', '<(res_loc)', '-I', '<(src_loc)',
+      '-o', '<(SHARED_INTERMEDIATE_DIR)/update_dependent_styles.timestamp',
       '<@(style_files)',
     ],
     'message': 'Updating dependent style files..',
@@ -46,7 +46,7 @@
     ],
     'action': [
       'python', '<(DEPTH)/update_dependent.py', '--qrc',
-      '-o<(SHARED_INTERMEDIATE_DIR)/update_dependent_qrc.timestamp',
+      '-o', '<(SHARED_INTERMEDIATE_DIR)/update_dependent_qrc.timestamp',
       '<@(qrc_files)',
     ],
     'message': 'Updating dependent qrc files..',
@@ -63,9 +63,9 @@
     ],
     'action': [
       '<(PRODUCT_DIR)/codegen_style<(exe_ext)',
-      '-I<(res_loc)', '-I<(src_loc)',
-      '-o<(SHARED_INTERMEDIATE_DIR)/styles',
-      '-w<(PRODUCT_DIR)/../..',
+      '-I', '<(res_loc)', '-I', '<(src_loc)',
+      '-o', '<(SHARED_INTERMEDIATE_DIR)/styles',
+      '-w', '<(PRODUCT_DIR)/../..',
 
       # GYP/Ninja bug workaround: if we specify just <(RULE_INPUT_PATH)
       # the <(RULE_INPUT_ROOT) variables won't be available in Ninja,
@@ -89,8 +89,8 @@
     ],
     'action': [
       '<(PRODUCT_DIR)/codegen_lang<(exe_ext)',
-      '-o<(SHARED_INTERMEDIATE_DIR)', '<(res_loc)/langs/lang.strings',
-      '-w<(PRODUCT_DIR)/../..',
+      '-o', '<(SHARED_INTERMEDIATE_DIR)', '<(res_loc)/langs/lang.strings',
+      '-w', '<(PRODUCT_DIR)/../..',
     ],
     'message': 'codegen_lang-ing lang.strings..',
     'process_outputs_as_sources': 1,
@@ -106,8 +106,8 @@
     ],
     'action': [
       '<(PRODUCT_DIR)/codegen_numbers<(exe_ext)',
-      '-o<(SHARED_INTERMEDIATE_DIR)', '<(res_loc)/numbers.txt',
-      '-w<(PRODUCT_DIR)/../..',
+      '-o', '<(SHARED_INTERMEDIATE_DIR)', '<(res_loc)/numbers.txt',
+      '-w', '<(PRODUCT_DIR)/../..',
     ],
     'message': 'codegen_numbers-ing numbers.txt..',
     'process_outputs_as_sources': 1,
@@ -123,7 +123,7 @@
     ],
     'action': [
       'python', '<(src_loc)/codegen/scheme/codegen_scheme.py',
-      '-o<(SHARED_INTERMEDIATE_DIR)', '<(res_loc)/scheme.tl',
+      '-o', '<(SHARED_INTERMEDIATE_DIR)', '<(res_loc)/scheme.tl',
     ],
     'message': 'codegen_scheme-ing scheme.tl..',
     'process_outputs_as_sources': 1,
@@ -138,7 +138,7 @@
     ],
     'action': [
       '<(PRODUCT_DIR)/codegen_emoji<(exe_ext)',
-      '-o<(SHARED_INTERMEDIATE_DIR)',
+      '-o', '<(SHARED_INTERMEDIATE_DIR)',
     ],
     'message': 'codegen_emoji-ing..',
     'process_outputs_as_sources': 1,
@@ -156,9 +156,9 @@
     ],
     'action': [
       '<(PRODUCT_DIR)/codegen_style<(exe_ext)',
-      '-I<(res_loc)', '-I<(src_loc)',
-      '-o<(SHARED_INTERMEDIATE_DIR)/styles',
-      '-w<(PRODUCT_DIR)/../..',
+      '-I', '<(res_loc)', '-I', '<(src_loc)',
+      '-o', '<(SHARED_INTERMEDIATE_DIR)/styles',
+      '-w', '<(PRODUCT_DIR)/../..',
 
       # GYP/Ninja bug workaround: if we specify just <(RULE_INPUT_PATH)
       # the <(RULE_INPUT_ROOT) variables won't be available in Ninja,
diff --git a/Telegram/gyp/refresh.bat b/Telegram/gyp/refresh.bat
index 3049291901..78caadc883 100644
--- a/Telegram/gyp/refresh.bat
+++ b/Telegram/gyp/refresh.bat
@@ -19,6 +19,8 @@ if not "%TDESKTOP_BUILD_DEFINES%" == "" (
   echo [INFO] Set build defines to !BUILD_DEFINES!
 )
 
+set GYP_MSVS_VERSION=2015
+
 cd "%FullScriptPath%"
 call gyp --depth=. --generator-output=../.. -Goutput_dir=out !BUILD_DEFINES! Telegram.gyp --format=ninja
 if %errorlevel% neq 0 goto error
diff --git a/docs/building-msvc.md b/docs/building-msvc.md
index 41846f3ec8..ee1d6229c8 100644
--- a/docs/building-msvc.md
+++ b/docs/building-msvc.md
@@ -277,8 +277,10 @@ run `git reset --hard HEAD` and execute `gclient` again
 <!-- -->
 
     git clone https://chromium.googlesource.com/external/gyp
+    cd gyp
+    git checkout a478c1ab51
     SET PATH=%PATH%;D:\TBuild\Libraries\gyp;D:\TBuild\Libraries\ninja;
-    cd ..\tdesktop\Telegram
+    cd ..\..\tdesktop\Telegram
 
 Also, actually add **D:\\TBuild\\Libraries\\ninja\\** (not just for running the **gyp** command) to your path environment variable, since Telegram needs it for the build process.