diff --git a/docs/rh-log.txt b/docs/rh-log.txt
index 0bad1e7f2..a4c378f7d 100644
--- a/docs/rh-log.txt
+++ b/docs/rh-log.txt
@@ -1,3 +1,8 @@
+April 3, 2008
+- Changed the Makefiles that are used by both Linux and MinGW so that msys
+  detection occurs only if $OS is Windows_NT. Otherwise, spurious nul files
+  are created when compiling on Linux.
+
 April 3, 2008 (Changes by Graf Zahl)
 - Fixed: The minimum parameter count for ACS_Execute and ACS_ExecuteAlways for
   DECORATE was wrong (2 instead of 1.)
diff --git a/snes_spc/Makefile b/snes_spc/Makefile
index 11c244759..f5c202d01 100644
--- a/snes_spc/Makefile
+++ b/snes_spc/Makefile
@@ -3,9 +3,9 @@
 CMD=0
 ifeq (Windows_NT,$(OS))
   CMD=1
-endif
-ifeq ($(findstring msys,$(shell sh --version 2>nul)),msys)
-  CMD=0
+  ifeq ($(findstring msys,$(shell sh --version 2>nul)),msys)
+    CMD=0
+  endif
 endif
 
 STATICLIB = libsnes_spc.a
diff --git a/src/sound/music_mus_midiout.cpp b/src/sound/music_mus_midiout.cpp
index c8a214931..f7b875cfe 100644
--- a/src/sound/music_mus_midiout.cpp
+++ b/src/sound/music_mus_midiout.cpp
@@ -50,10 +50,6 @@
 
 // EXTERNAL DATA DECLARATIONS ----------------------------------------------
 
-#ifdef _WIN32
-extern UINT mididevice;
-#endif
-
 // PRIVATE DATA DEFINITIONS ------------------------------------------------
 
 static const BYTE CtrlTranslate[15] =
diff --git a/tools/dehsupp/Makefile b/tools/dehsupp/Makefile
index 2502093ce..35c09b5a7 100644
--- a/tools/dehsupp/Makefile
+++ b/tools/dehsupp/Makefile
@@ -1,10 +1,9 @@
 ifeq (Windows_NT,$(OS))
   WIN=1
   WINCMD=1
-endif
-ifeq ($(findstring msys,$(shell sh --version 2>nul)),msys)
-  WIN=1
-  WINCMD=0
+  ifeq ($(findstring msys,$(shell sh --version 2>nul)),msys)
+    WINCMD=0
+  endif
 endif
 
 ifeq (1,$(WIN))
diff --git a/tools/lemon/Makefile b/tools/lemon/Makefile
index c9d4774ac..bb1d88c6e 100644
--- a/tools/lemon/Makefile
+++ b/tools/lemon/Makefile
@@ -1,10 +1,9 @@
 ifeq (Windows_NT,$(OS))
   WIN=1
   WINCMD=1
-endif
-ifeq ($(findstring msys,$(shell sh --version 2>nul)),msys)
-  WIN=1
-  WINCMD=0
+  ifeq ($(findstring msys,$(shell sh --version 2>nul)),msys)
+    WINCMD=0
+  endif
 endif
 
 ifeq (1,$(WIN))
diff --git a/tools/makewad/Makefile b/tools/makewad/Makefile
index b81fdeede..f79212d5f 100644
--- a/tools/makewad/Makefile
+++ b/tools/makewad/Makefile
@@ -1,10 +1,9 @@
 ifeq (Windows_NT,$(OS))
   WIN=1
   WINCMD=1
-endif
-ifeq ($(findstring msys,$(shell sh --version 2>nul)),msys)
-  WIN=1
-  WINCMD=0
+  ifeq ($(findstring msys,$(shell sh --version 2>nul)),msys)
+    WINCMD=0
+  endif
 endif
 
 ifeq (1,$(WIN))
diff --git a/tools/re2c/Makefile b/tools/re2c/Makefile
index 05e7601cb..9261a7813 100644
--- a/tools/re2c/Makefile
+++ b/tools/re2c/Makefile
@@ -1,10 +1,9 @@
 ifeq (Windows_NT,$(OS))
   WIN=1
   WINCMD=1
-endif
-ifeq ($(findstring msys,$(shell sh --version 2>nul)),msys)
-  WIN=1
-  WINCMD=0
+  ifeq ($(findstring msys,$(shell sh --version 2>nul)),msys)
+    WINCMD=0
+  endif
 endif
 
 ifeq (1,$(WIN))
diff --git a/tools/updaterevision/Makefile b/tools/updaterevision/Makefile
index 20f09049f..0f54cb382 100644
--- a/tools/updaterevision/Makefile
+++ b/tools/updaterevision/Makefile
@@ -1,10 +1,9 @@
 ifeq (Windows_NT,$(OS))
   WIN=1
   WINCMD=1
-endif
-ifeq ($(findstring msys,$(shell sh --version 2>nul)),msys)
-  WIN=1
-  WINCMD=0
+  ifeq ($(findstring msys,$(shell sh --version 2>nul)),msys)
+    WINCMD=0
+  endif
 endif
 
 CC = gcc