diff --git a/gcc/fortran/ChangeLog b/gcc/fortran/ChangeLog
index cbdf82d63eb4..987bc50d5397 100644
--- a/gcc/fortran/ChangeLog
+++ b/gcc/fortran/ChangeLog
@@ -1,3 +1,9 @@
+2007-03-08  Paul Thomas  <pault@gcc.gnu.org>
+
+	PR fortran/31011
+	* expr.c (find_array_section): Correct arithmetic for section
+	size.
+
 2007-03-07  Brooks Moses  <brooks.moses@codesourcery.com>
 
 	* iresolve.c (gfc_resolve_ishftc): Correct s_kind value.
diff --git a/gcc/fortran/expr.c b/gcc/fortran/expr.c
index dbe51888656b..06f4d20ef45c 100644
--- a/gcc/fortran/expr.c
+++ b/gcc/fortran/expr.c
@@ -1137,8 +1137,7 @@ find_array_section (gfc_expr *expr, gfc_ref *ref)
 	    }
 
 	  /* Calculate the number of elements and the shape.  */
-	  mpz_abs (tmp_mpz, stride[d]);
-	  mpz_div (tmp_mpz, stride[d], tmp_mpz);
+	  mpz_set (tmp_mpz, stride[d]);
 	  mpz_add (tmp_mpz, end[d], tmp_mpz);
 	  mpz_sub (tmp_mpz, tmp_mpz, ctr[d]);
 	  mpz_div (tmp_mpz, tmp_mpz, stride[d]);
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 81dd95db41bd..6267c8ad8fd3 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2007-03-08  Paul Thomas  <pault@gcc.gnu.org>
+
+	PR fortran/31011
+	* gfortran.dg/parameter_array_section_2.f90: New test.
+
 2007-03-08  Volker Reichelt  <reichelt@netcologne.de>
 
 	PR c++/30852
diff --git a/gcc/testsuite/gfortran.dg/parameter_array_section_2.f90 b/gcc/testsuite/gfortran.dg/parameter_array_section_2.f90
new file mode 100644
index 000000000000..aa212c050fa9
--- /dev/null
+++ b/gcc/testsuite/gfortran.dg/parameter_array_section_2.f90
@@ -0,0 +1,14 @@
+! { dg-do run }
+! { dg-options "-O" }
+! Test the fix for PR31011 in which the length of the array sections
+! with stride other than unity were incorrectly calculated.
+!
+! Contributed by <terry@chem.gu.se>
+!
+program PotentialMatrix
+ implicit none
+ real(kind=8),dimension(2),parameter::v2=(/1,2/)
+ real(kind=8),dimension(4),parameter::v4=(/1,2,3,4/)
+ if (any (v2*v4(1:3:2) .ne. (/1,6/))) call abort ()
+ if (any (v2*v4(3:1:-2) .ne. (/3,2/))) call abort ()
+end