diff --git a/ChangeLog b/ChangeLog
index a157eb2e..0e0227b2 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -3,6 +3,7 @@
 - reorder file tests to put slow loaders last
 - ifthenelse needs less C stack during eval
 - better rounding in bilinear interpolator
+- fix to "make check" in non-C locales
 
 1/1/16 started 8.2.1
 - add a compat stub, thanks Benjamin
diff --git a/test/variables.sh.in b/test/variables.sh.in
index dd3fe898..f2751c31 100644
--- a/test/variables.sh.in
+++ b/test/variables.sh.in
@@ -7,3 +7,6 @@ mkdir -p $tmp
 vips=$top_srcdir/tools/vips
 vipsthumbnail=$top_srcdir/tools/vipsthumbnail
 vipsheader=$top_srcdir/tools/vipsheader
+
+# we need bc to use '.' for a decimal separator
+export LC_NUMERIC=C