diff --git a/Makefile.in b/Makefile.in
index 5fd926c4238..1a92ca8aaf3 100644
--- a/Makefile.in
+++ b/Makefile.in
@@ -164,7 +164,8 @@ bitmapdir=@bitmapdir@
 # We use $(srcdir) explicitly in dependencies so as not to depend on VPATH.
 srcdir=@srcdir@
 abs_srcdir=@abs_srcdir@
-abs_top_srcdir=@abs_top_srcdir@	# MinGW CPPFLAGS may use this
+# MinGW CPPFLAGS may use this.
+abs_top_srcdir=@abs_top_srcdir@
 
 # Where the manpage source files are kept.
 mansrcdir=$(srcdir)/doc/man
diff --git a/lib-src/Makefile.in b/lib-src/Makefile.in
index e4d104e0200..3843f549679 100644
--- a/lib-src/Makefile.in
+++ b/lib-src/Makefile.in
@@ -84,7 +84,8 @@ VPATH=@srcdir@
 
 # The top-level source directory, also set by configure.
 top_srcdir=@top_srcdir@
-abs_top_srcdir=@abs_top_srcdir@	# MinGW CPPFLAGS may use this
+# MinGW CPPFLAGS may use this.
+abs_top_srcdir=@abs_top_srcdir@
 
 # ==================== Emacs-specific directories ====================
 
diff --git a/lwlib/Makefile.in b/lwlib/Makefile.in
index c463efb05e2..b7f1673aca9 100644
--- a/lwlib/Makefile.in
+++ b/lwlib/Makefile.in
@@ -23,7 +23,8 @@
 # and set up to be configured by ../configure.
 
 srcdir=@srcdir@
-abs_top_srcdir=@abs_top_srcdir@	# MinGW CPPFLAGS may use this
+# MinGW CPPFLAGS may use this.
+abs_top_srcdir=@abs_top_srcdir@
 VPATH=@srcdir@
 @SET_MAKE@
 C_SWITCH_X_SITE=@C_SWITCH_X_SITE@
diff --git a/nt/Makefile.in b/nt/Makefile.in
index 7606b31ef40..8bd37e7983c 100644
--- a/nt/Makefile.in
+++ b/nt/Makefile.in
@@ -76,7 +76,8 @@ VPATH=@srcdir@
 
 # The top-level source directory, also set by configure.
 top_srcdir=@top_srcdir@
-abs_top_srcdir=@abs_top_srcdir@	# MinGW CPPFLAGS may use this
+# MinGW CPPFLAGS may use this.
+abs_top_srcdir=@abs_top_srcdir@
 
 # ==================== Emacs-specific directories ====================
 
diff --git a/oldXMenu/Makefile.in b/oldXMenu/Makefile.in
index f0c93e10cd4..8b0e8391278 100644
--- a/oldXMenu/Makefile.in
+++ b/oldXMenu/Makefile.in
@@ -43,7 +43,8 @@
 ### Code:
 
 srcdir=@srcdir@
-abs_top_srcdir=@abs_top_srcdir@	# MinGW CPPFLAGS may use this
+# MinGW CPPFLAGS may use this.
+abs_top_srcdir=@abs_top_srcdir@
 VPATH=@srcdir@
 C_SWITCH_X_SITE=@C_SWITCH_X_SITE@
 C_SWITCH_SYSTEM=@C_SWITCH_SYSTEM@
diff --git a/src/Makefile.in b/src/Makefile.in
index 29acb4e7380..21d92463f20 100644
--- a/src/Makefile.in
+++ b/src/Makefile.in
@@ -28,7 +28,8 @@ SHELL = @SHELL@
 # Here are the things that we expect ../configure to edit.
 # We use $(srcdir) explicitly in dependencies so as not to depend on VPATH.
 srcdir = @srcdir@
-abs_top_srcdir=@abs_top_srcdir@	# MinGW CPPFLAGS may use this
+# MinGW CPPFLAGS may use this.
+abs_top_srcdir=@abs_top_srcdir@
 ntsource = $(srcdir)/../nt
 abs_builddir = @abs_builddir@
 VPATH = $(srcdir)