diff --git a/appveyor.yml b/appveyor.yml
index 25b95d292..b0544a90b 100644
--- a/appveyor.yml
+++ b/appveyor.yml
@@ -47,7 +47,7 @@ before_build:
 - upx -V
 - ccache -V
 - ccache -s
-- set SRB2_MFLAGS=-C src MINGW=1 WARNINGMODE=1 GCC53=1 CCACHE=1
+- set SRB2_MFLAGS=-C src MINGW=1 WARNINGMODE=1 GCC63=1 CCACHE=1
 
 build_script:
 - cmd: mingw32-make.exe %SRB2_MFLAGS% %CONFIGURATION%=1 clean
diff --git a/src/Makefile.cfg b/src/Makefile.cfg
index 72404becc..80d018c4b 100644
--- a/src/Makefile.cfg
+++ b/src/Makefile.cfg
@@ -7,6 +7,23 @@
 # and other things
 #
 
+
+ifdef GCC63
+GCC62=1
+endif
+
+ifdef GCC62
+GCC61=1
+endif
+
+ifdef GCC61
+GCC54=1
+endif
+
+ifdef GCC54
+GCC53=1
+endif
+
 ifdef GCC53
 GCC52=1
 endif
@@ -164,19 +181,29 @@ ifdef GCC45
 WFLAGS+=-Wunsuffixed-float-constants
 endif
 endif
+
 ifdef NOLDWARNING
 LDFLAGS+=-Wl,--as-needed
 endif
+
 ifdef ERRORMODE
 WFLAGS+=-Werror
 endif
+
+WFLAGS+=$(OLDWFLAGS)
+
 ifdef GCC43
  #WFLAGS+=-Wno-error=clobbered
 endif
 ifdef GCC46
  WFLAGS+=-Wno-error=suggest-attribute=noreturn
 endif
-WFLAGS+=$(OLDWFLAGS)
+ifdef GCC54
+ WFLAGS+=-Wno-logical-op -Wno-error=logical-op
+endif
+ifdef GCC61
+ WFLAGS+=-Wno-tautological-compare -Wno-error=tautological-compare
+endif
 
 
 #indicate platform and what interface use with
diff --git a/src/d_net.c b/src/d_net.c
index fae1ea311..7f16c302d 100644
--- a/src/d_net.c
+++ b/src/d_net.c
@@ -991,12 +991,14 @@ void Command_Droprate(void)
 	packetdroprate = droprate;
 }
 
+#ifndef NONET
 static boolean ShouldDropPacket(void)
 {
 	return (packetdropquantity[netbuffer->packettype])
 		|| (packetdroprate != 0 && rand() < (RAND_MAX * (packetdroprate / 100.f))) || packetdroprate == 100;
 }
 #endif
+#endif
 
 //
 // HSendPacket
diff --git a/src/hardware/r_opengl/r_opengl.c b/src/hardware/r_opengl/r_opengl.c
index 54dd94854..3a0bf7054 100644
--- a/src/hardware/r_opengl/r_opengl.c
+++ b/src/hardware/r_opengl/r_opengl.c
@@ -1836,7 +1836,7 @@ EXPORT void HWRAPI(SetSpecialState) (hwdspecialstate_t IdState, INT32 Value)
 	}
 }
 
-static inline void DrawMD2Ex(INT32 *gl_cmd_buffer, md2_frame_t *frame, UINT32 duration, UINT32 tics, md2_frame_t *nextframe, FTransform *pos, float scale, UINT8 flipped, UINT8 *color)
+static  void DrawMD2Ex(INT32 *gl_cmd_buffer, md2_frame_t *frame, UINT32 duration, UINT32 tics, md2_frame_t *nextframe, FTransform *pos, float scale, UINT8 flipped, UINT8 *color)
 {
 	INT32     val, count, pindex;
 	GLfloat s, t;