diff --git a/core/c/jbigi/build-all.sh b/core/c/jbigi/build-all.sh
index 0b1502724..f3da059a0 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 1a6ca48a3..20a3f4acf 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