diff --git a/client/CMakeLists.txt b/client/CMakeLists.txt
index b23747b72..0bbf1067c 100644
--- a/client/CMakeLists.txt
+++ b/client/CMakeLists.txt
@@ -12,8 +12,6 @@ if(CMAKE_VERSION VERSION_LESS "3.7.0")
     set(CMAKE_INCLUDE_CURRENT_DIR ON)
 endif()
 
-set(CMAKE_CXX_STANDARD 14)
-
 if(APPLE AND EXISTS /usr/local/opt/qt5)
     # Homebrew installs Qt5 (up to at least 5.11.0) in
     # /usr/local/qt5. Ensure that it can be found by CMake
diff --git a/client/Makefile b/client/Makefile
index cef9939f8..ed133eb36 100644
--- a/client/Makefile
+++ b/client/Makefile
@@ -57,7 +57,7 @@ LIBS = -I$(LUALIBPATH) -I$(MBEDTLSLIBPATH) -I$(JANSSONLIBPATH) -I$(CBORLIBPATH)
 INCLUDES_CLIENT = -I./src -I../include -I../common -I../common_fpga $(LIBS)
 CFLAGS ?= -Wall -Werror -O3
 # We cannot just use CFLAGS+=... because it has impact on sub-makes if CFLAGS is defined in env:
-PM3CFLAGS = $(CFLAGS) -std=c99 $(INCLUDES_CLIENT)
+PM3CFLAGS = $(CFLAGS) $(INCLUDES_CLIENT)
 # WIP Testing
 #PM3CFLAGS = $(CFLAGS) -std=c11 -pedantic $(INCLUDES_CLIENT)
 PREFIX ?= /usr/local
@@ -101,7 +101,7 @@ ifneq ($(SKIPQT),1)
         MOC = $(shell pkg-config --variable=moc_location QtCore)
         UIC = $(shell pkg-config --variable=uic_location QtCore)
     else
-        PM3CXXFLAGS += -std=c++11 -fPIC
+        PM3CXXFLAGS += -fPIC
     endif
     ifeq ($(QTINCLUDES), )
     # if both pkg-config commands failed, search in common places
@@ -111,7 +111,7 @@ ifneq ($(SKIPQT),1)
             ifneq ($(wildcard $(QTDIR)/include/QtWidgets),)
                 QTINCLUDES += -I$(QTDIR)/include/QtWidgets
                 QTLDLIBS = -L$(QTDIR)/lib -lQt5Widgets -lQt5Gui -lQt5Core
-                PM3CXXFLAGS += -std=c++11 -fPIC
+                PM3CXXFLAGS += -fPIC
             endif
             MOC = $(QTDIR)/bin/moc
             UIC = $(QTDIR)/bin/uic
diff --git a/client/deps/amiibo.cmake b/client/deps/amiibo.cmake
index dd185fc91..857074f9e 100644
--- a/client/deps/amiibo.cmake
+++ b/client/deps/amiibo.cmake
@@ -5,8 +5,6 @@
 #amiitool.c $(MYSRCS) ../../../../common/../../commonutil.c ../ui.c -lreadline -lm ../../../../common/mbedtls/libmbedtls.a \
 #-o amiitool
 
-set_property(SOURCE PROPERTY C_STANDARD 99)
-
 add_library(amiibo STATIC
         amiitool/amiibo.c
         amiitool/drbg.c
diff --git a/client/deps/amiitool/Makefile b/client/deps/amiitool/Makefile
index ff2c0da88..7fe532878 100644
--- a/client/deps/amiitool/Makefile
+++ b/client/deps/amiitool/Makefile
@@ -1,6 +1,6 @@
 MYSRCPATHS =
 MYINCLUDES = -I. -I.. -I../jansson -I../../../common -I../../../include
-MYCFLAGS = -std=c99 -D_ISOC99_SOURCE
+MYCFLAGS =
 MYDEFS =
 MYSRCS = \
 	amiibo.c \
diff --git a/client/deps/cliparser/Makefile b/client/deps/cliparser/Makefile
index e1c5b2356..7f4409de0 100644
--- a/client/deps/cliparser/Makefile
+++ b/client/deps/cliparser/Makefile
@@ -1,6 +1,6 @@
 MYSRCPATHS =
 MYINCLUDES = -I../../../common -I../../../include -I../../src
-MYCFLAGS = -std=c99 -D_ISOC99_SOURCE
+MYCFLAGS =
 MYDEFS =
 MYSRCS = \
 	argtable3.c \
diff --git a/client/deps/hardnested.cmake b/client/deps/hardnested.cmake
index b9ca14dab..8945d68a8 100644
--- a/client/deps/hardnested.cmake
+++ b/client/deps/hardnested.cmake
@@ -1,5 +1,3 @@
-set_property(SOURCE PROPERTY C_STANDARD 99)
-
 add_library(hardnested_nosimd OBJECT
         hardnested/hardnested_bf_core.c
         hardnested/hardnested_bitarray_core.c)
diff --git a/client/deps/hardnested/Makefile b/client/deps/hardnested/Makefile
index 84c4ce842..483a3283b 100644
--- a/client/deps/hardnested/Makefile
+++ b/client/deps/hardnested/Makefile
@@ -1,6 +1,6 @@
 MYSRCPATHS =
 MYINCLUDES = -I../../../common -I../../../include -I../../src -I../jansson
-MYCFLAGS = -std=c99 -D_ISOC99_SOURCE
+MYCFLAGS =
 MYDEFS =
 MYSRCS = hardnested_bruteforce.c
 
diff --git a/client/deps/hardnested/hardnested_tables.c b/client/deps/hardnested/hardnested_tables.c
index 91e3b3cd3..d3c620fe5 100644
--- a/client/deps/hardnested/hardnested_tables.c
+++ b/client/deps/hardnested/hardnested_tables.c
@@ -20,7 +20,7 @@
 //-----------------------------------------------------------------------------
 
 // To compile it:
-// gcc -std=c99 -I ../../common -o hardnested_tables hardnested_tables.c
+// gcc -I../../../common -I../../../include -o hardnested_tables hardnested_tables.c
 
 #include <inttypes.h>
 #include <stdbool.h>
diff --git a/client/deps/jansson.cmake b/client/deps/jansson.cmake
index b2042c6b4..216f7a830 100644
--- a/client/deps/jansson.cmake
+++ b/client/deps/jansson.cmake
@@ -1,5 +1,3 @@
-set_property(SOURCE PROPERTY C_STANDARD 99)
-
 add_library(jansson STATIC
         jansson/dump.c
         jansson/error.c
diff --git a/client/deps/jansson/Makefile b/client/deps/jansson/Makefile
index 111aed087..152e8bcb9 100644
--- a/client/deps/jansson/Makefile
+++ b/client/deps/jansson/Makefile
@@ -1,6 +1,6 @@
 MYSRCPATHS =
 MYINCLUDES = -I.
-MYCFLAGS = -std=c99 -D_ISOC99_SOURCE -Wno-unused-function
+MYCFLAGS = -Wno-unused-function
 MYDEFS = -DHAVE_STDINT_H
 MYSRCS = \
 	dump.c \
diff --git a/client/deps/liblua/Makefile b/client/deps/liblua/Makefile
index 692684186..54e45185b 100644
--- a/client/deps/liblua/Makefile
+++ b/client/deps/liblua/Makefile
@@ -1,7 +1,6 @@
 MYSRCPATHS =
 MYINCLUDES = -I.
-# Lua lib is not ready for C99 style...
-#MYCFLAGS = -std=c99 -D_ISOC99_SOURCE
+# Lua lib requires GNU extensions (implicit declarations of functions): -std=gnu99 or -std=gnu11
 MYCFLAGS =
 MYDEFS = -DLUA_COMPAT_ALL $(SYSCFLAGS)
 MYSRCS =	lapi.c lcode.c lctype.c ldebug.c ldo.c ldump.c lfunc.c lgc.c llex.c \
diff --git a/client/deps/mbedtls.cmake b/client/deps/mbedtls.cmake
index 13b08bec0..932c1757c 100644
--- a/client/deps/mbedtls.cmake
+++ b/client/deps/mbedtls.cmake
@@ -1,5 +1,3 @@
-set_property(SOURCE PROPERTY C_STANDARD 99)
-
 add_library(mbedtls STATIC
         ../../common/mbedtls/aes.c
         ../../common/mbedtls/asn1parse.c
diff --git a/client/deps/reveng.cmake b/client/deps/reveng.cmake
index 0bf84d05a..0d24c9d49 100644
--- a/client/deps/reveng.cmake
+++ b/client/deps/reveng.cmake
@@ -1,5 +1,3 @@
-set_property(SOURCE PROPERTY C_STANDARD 99)
-
 add_library(reveng STATIC
         reveng/bmpbit.c
         reveng/cli.c
diff --git a/client/deps/reveng/Makefile b/client/deps/reveng/Makefile
index 93c363d70..1794b0bdb 100644
--- a/client/deps/reveng/Makefile
+++ b/client/deps/reveng/Makefile
@@ -5,7 +5,7 @@
 
 MYSRCPATHS =
 MYINCLUDES = -I../cliparser
-MYCFLAGS = -std=c99 -D_ISOC99_SOURCE
+MYCFLAGS =
 MYDEFS = -DPRESETS
 MYSRCS = \
 	bmpbit.c \
diff --git a/client/deps/tinycbor/Makefile b/client/deps/tinycbor/Makefile
index 713b6e428..99039ac98 100644
--- a/client/deps/tinycbor/Makefile
+++ b/client/deps/tinycbor/Makefile
@@ -1,7 +1,6 @@
 MYSRCPATHS =
 MYINCLUDES =
 # Strange errors on Mingw when compiling with C99
-#MYCFLAGS = -std=c99 -D_ISOC99_SOURCE
 MYCFLAGS =
 MYDEFS =
 MYSRCS = \
diff --git a/client/deps/zlib.cmake b/client/deps/zlib.cmake
index 882022ab5..dc6044f80 100644
--- a/client/deps/zlib.cmake
+++ b/client/deps/zlib.cmake
@@ -1,5 +1,3 @@
-set_property(SOURCE PROPERTY C_STANDARD 99)
-
 add_library(z STATIC
         ../../common/zlib/deflate.c
         ../../common/zlib/adler32.c
diff --git a/common/mbedtls/Makefile b/common/mbedtls/Makefile
index 52663d67e..be5f08a0a 100644
--- a/common/mbedtls/Makefile
+++ b/common/mbedtls/Makefile
@@ -1,6 +1,6 @@
 MYSRCPATHS =
 MYINCLUDES = -I. -I..
-MYCFLAGS = -std=c99 -D_ISOC99_SOURCE
+MYCFLAGS =
 MYDEFS =
 MYSRCS = \
 	aes.c \
diff --git a/common/zlib/Makefile b/common/zlib/Makefile
index b62071d5d..acc35bf42 100644
--- a/common/zlib/Makefile
+++ b/common/zlib/Makefile
@@ -1,7 +1,7 @@
 MYSRCPATHS = ../../common/zlib
 MYSRCS     = deflate.c adler32.c trees.c zutil.c inflate.c inffast.c inftrees.c
 MYINCLUDES = -I../../common/zlib
-MYCFLAGS   = -std=c99 -D_ISOC99_SOURCE
+MYCFLAGS   =
 MYDEFS     = -DZ_SOLO -DNO_GZIP -DZLIB_PM3_TUNED
 #-DDEBUG -Dverbose=1
 
diff --git a/tools/mfkey/Makefile b/tools/mfkey/Makefile
index a7b006f6e..fd69207a7 100644
--- a/tools/mfkey/Makefile
+++ b/tools/mfkey/Makefile
@@ -1,7 +1,7 @@
 MYSRCPATHS = ../../common ../../common/crapto1
 MYSRCS = crypto1.c crapto1.c bucketsort.c
 MYINCLUDES = -I../../include -I../../common
-MYCFLAGS = -std=c99 -D_ISOC99_SOURCE
+MYCFLAGS =
 MYDEFS =
 
 BINS = mfkey32 mfkey32v2 mfkey64
@@ -9,6 +9,13 @@ INSTALLTOOLS = $(BINS)
 
 include ../../Makefile.host
 
+# checking platform can be done only after Makefile.host
+ifneq (,$(findstring MINGW,$(platform)))
+    # Mingw uses by default Microsoft printf, we want the GNU printf (e.g. for %z)
+    # and setting _ISOC99_SOURCE sets internally __USE_MINGW_ANSI_STDIO=1
+    CFLAGS += -D_ISOC99_SOURCE
+endif
+
 mfkey32 : $(OBJDIR)/mfkey32.o $(MYOBJS)
 mfkey32v2 : $(OBJDIR)/mfkey32v2.o $(MYOBJS)
 mfkey64 : $(OBJDIR)/mfkey64.o $(MYOBJS)
diff --git a/tools/nonce2key/Makefile b/tools/nonce2key/Makefile
index 77dc18099..a4b0bde05 100644
--- a/tools/nonce2key/Makefile
+++ b/tools/nonce2key/Makefile
@@ -1,7 +1,7 @@
 MYSRCPATHS = ../../common ../../common/crapto1
 MYSRCS = crypto1.c crapto1.c bucketsort.c
 MYINCLUDES = -I../../include -I../../common
-MYCFLAGS = -std=c99 -D_ISOC99_SOURCE
+MYCFLAGS =
 MYDEFS =
 
 BINS = nonce2key
@@ -9,4 +9,11 @@ INSTALLTOOLS = $(BINS)
 
 include ../../Makefile.host
 
+# checking platform can be done only after Makefile.host
+ifneq (,$(findstring MINGW,$(platform)))
+    # Mingw uses by default Microsoft printf, we want the GNU printf (e.g. for %z)
+    # and setting _ISOC99_SOURCE sets internally __USE_MINGW_ANSI_STDIO=1
+    CFLAGS += -D_ISOC99_SOURCE
+endif
+
 nonce2key : $(OBJDIR)/nonce2key.o $(MYOBJS)