diff --git a/core/c/jbigi/build-all.sh b/core/c/jbigi/build-all.sh
index 0b1502724889ce2d8e8b57d1f4641d1b4b2685b2..f3da059a0657c23c06eafb466b38e783922b6978 100644
--- a/core/c/jbigi/build-all.sh
+++ b/core/c/jbigi/build-all.sh
@@ -13,7 +13,7 @@ FreeBSD*)
 esac
 
 echo "Extracting GMP..."
-tar -xzf gmp-4.1.3.tar.gz
+tar -xjf gmp-4.1.3.tar.bz2
 echo "Building..."
 mkdir bin
 mkdir lib
diff --git a/core/c/jbigi/build.sh b/core/c/jbigi/build.sh
index 1a6ca48a349fe3e56d8f7e056863b29a15cf1697..20a3f4acf9f08b6cc5ddb02dabdf9a558169995b 100644
--- a/core/c/jbigi/build.sh
+++ b/core/c/jbigi/build.sh
@@ -15,7 +15,7 @@ FreeBSD*)
 esac
 
 echo "Extracting GMP..."
-tar -xzf gmp-4.1.3.tar.gz
+tar -xjf gmp-4.1.3.tar.bz2
 echo "Building..."
 mkdir bin
 mkdir lib