--- a/doc/interpreter/images.awk
+++ b/doc/interpreter/images.awk
@@ -27,7 +27,7 @@
     for (j = 2; j <= NF; j++) {
       printf ("%s.%s: %s\n", $j, ext, script);
       printf ("\t$(top_builddir)/run-octave -f -q -H -p $(srcdir) --eval \"%s ('%s', '%s');\"\n",
-	      basename, $j, ext);
+              basename, $j, ext);
     }
   }
 }

--- a/libinterp/dldfcn/config-module.awk
+++ b/libinterp/dldfcn/config-module.awk
@@ -61,7 +61,7 @@
     sub (/\.cc$/, "", basename);
     print "";
     printf ("dldfcn_%s_la_SOURCES = dldfcn/%s\n",
-	    basename, files[i]);
+            basename, files[i]);
     if (cppflags[i])
       {
         printf ("dldfcn/%s.df: CPPFLAGS += %s\n",

--- a/libinterp/octave-value/module.mk
+++ b/libinterp/octave-value/module.mk
@@ -154,7 +154,7 @@
 
 octave_value_liboctave_value_la_CPPFLAGS = \
   $(liboctinterp_la_CPPFLAGS) \
-	$(HDF5_CPPFLAGS) \
+  $(HDF5_CPPFLAGS) \
   $(JAVA_CPPFLAGS)
 
 octave_value_liboctave_value_la_LIBADD = $(JAVA_LIBS)

--- a/m4/module.mk
+++ b/m4/module.mk
@@ -3,7 +3,7 @@
   m4/ax_blas.m4 \
   m4/ax_blas_f77_func.m4 \
   m4/ax_compare_version.m4 \
-  m4/ax_lapack.m4	\
+  m4/ax_lapack.m4 \
   m4/ax_pthread.m4 \
   m4/gnulib-cache.m4 \
   m4/libtool.m4 \

--- a/scripts/java/org/octave/Matrix.java
+++ b/scripts/java/org/octave/Matrix.java
@@ -47,7 +47,7 @@
     int n = (m > 0 ? data[0].length : 0);
     int idx = 0;
     double[] buf = new double[m*n];
-		
+
     for (int j = 0; j < n; j++)
       for (int i = 0; i < m; i++)
         buf[idx++] = data[i][j];
@@ -257,7 +257,7 @@
 
     return null;
   }
-	
+
   public double[][][] asDoubleMatrix3 ()
   {
     if (cache != null)

--- a/scripts/miscellaneous/module.mk
+++ b/scripts/miscellaneous/module.mk
@@ -24,7 +24,7 @@
   miscellaneous/dump_prefs.m \
   miscellaneous/edit.m \
   miscellaneous/error_ids.m \
-	miscellaneous/fact.m \
+  miscellaneous/fact.m \
   miscellaneous/fileattrib.m \
   miscellaneous/fileparts.m \
   miscellaneous/fullfile.m \

--- a/scripts/sparse/module.mk
+++ b/scripts/sparse/module.mk
@@ -1,7 +1,7 @@
 FCN_FILE_DIRS += sparse
 
 sparse_PRIVATE_FCN_FILES = \
-	sparse/private/__sprand_impl__.m
+  sparse/private/__sprand_impl__.m
 
 sparse_FCN_FILES = \
   sparse/bicg.m \
@@ -29,7 +29,7 @@
   sparse/svds.m \
   sparse/treelayout.m \
   sparse/treeplot.m \
-	$(sparse_PRIVATE_FCN_FILES)
+  $(sparse_PRIVATE_FCN_FILES)
 
 FCN_FILES += $(sparse_FCN_FILES)
 

--- a/scripts/startup/main-rcfile
+++ b/scripts/startup/main-rcfile
@@ -7,8 +7,8 @@
 ## directory.
 
 readline_read_init_file (sprintf ("%s%s%s",
-				  octave_config_info ("startupfiledir"),
-				  filesep, "inputrc"));
+                                  octave_config_info ("startupfiledir"),
+                                  filesep, "inputrc"));
 
 if (strcmp (PAGER (), "less") && isempty (getenv ("LESS")))
   PAGER_FLAGS ('-e -X -P"-- less ?pB(%pB\\%):--. (f)orward, (b)ack, (q)uit$"');

--- a/test/build-sparse-tests.sh
+++ b/test/build-sparse-tests.sh
@@ -231,7 +231,7 @@
 
 gen_function() {
     if $preset; then
-	cat >>$TESTS <<EOF
+        cat >>$TESTS <<EOF
 ##
 ## test_sparse
 ##
@@ -243,7 +243,7 @@
 
 EOF
     else
-	cat >>$TESTS <<EOF
+        cat >>$TESTS <<EOF
 ##
 ## test_sprandom
 ##

--- a/test/ctor-vs-method/@parent/parent.m
+++ b/test/ctor-vs-method/@parent/parent.m
@@ -6,9 +6,9 @@
     switch class (a)
       case 'parent'
         %% copy constructor
-	rot = a;
+        rot = a;
       otherwise
-	error ('type mismatch in parent constructor')
+        error ('type mismatch in parent constructor')
     end
   end
   __trace__ ('end parent/parent');