diff --git a/CHANGES b/CHANGES
--- a/CHANGES
+++ b/CHANGES
@@ -130,3 +130,6 @@
 
 0.2.7:
 		Update build configuration : copied from hmatrix		
+
+0.2.7.1:
+		added gsl dependencies to cabal file
diff --git a/hsignal.cabal b/hsignal.cabal
--- a/hsignal.cabal
+++ b/hsignal.cabal
@@ -1,8 +1,8 @@
 Name:               hsignal
-Version:            0.2.7
+Version:            0.2.7.1
 License:            BSD3
 License-file:       LICENSE
-Copyright:          (c) A.V.H. McPhail 2010, 2011, 2014, 2105
+Copyright:          (c) A.V.H. McPhail 2010, 2011, 2014, 2015
 Author:             Vivian McPhail
 Maintainer:         haskell.vivian.mcphail <at> gmail <dot> com
 Stability:          provisional
@@ -30,6 +30,10 @@
     description:    Link with OpenBLAS (https://github.com/xianyi/OpenBLAS) optimized libraries.
     default:        False
 
+flag onlygsl
+    description:    don't link gslcblas
+    default:        False
+
 library
 
     Build-Depends:      base >= 4 && < 5,
@@ -65,13 +69,14 @@
         extra-lib-dirs:     /usr/lib/openblas/lib    
         extra-libraries:    openblas
     else 
-        extra-libraries:    blas lapack
+        extra-libraries:    blas lapack 
 
     if os(OSX)
         extra-lib-dirs: /opt/local/lib/
         include-dirs: /opt/local/include/
         extra-lib-dirs: /usr/local/lib/
         include-dirs: /usr/local/include/
+        extra-libraries: gsl
         if arch(i386)
             cc-options: -arch i386
         frameworks: Accelerate
@@ -79,14 +84,20 @@
     if os(freebsd)
        extra-lib-dirs: /usr/local/lib
        include-dirs: /usr/local/include
-       extra-libraries: blas lapack gfortran
+       extra-libraries: blas lapack gfortran gsl
 
     if os(windows)
-        extra-libraries: blas lapack
+        extra-libraries: blas lapack gsl-0
 
     if os(linux)
         if arch(x86_64)
             cc-options: -fPIC
+
+    if flag(onlygsl)
+      extra-libraries: gsl
+    else
+      pkgconfig-depends: gsl
+
 
 source-repository head
     type:     git