diff --git a/include/vips/inlines.h b/include/vips/inlines.h
new file mode 100644
index 00000000..9d1a60e6
--- /dev/null
+++ b/include/vips/inlines.h
@@ -0,0 +1,70 @@
+/* Inline maths functions if they are missing from libm
+ */
+
+/*
+
+    This file is part of VIPS.
+
+    VIPS is free software; you can redistribute it and/or modify
+    it under the terms of the GNU Lesser General Public License as published by
+    the Free Software Foundation; either version 2 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU Lesser General Public License for more details.
+
+    You should have received a copy of the GNU Lesser General Public License
+    along with this program; if not, write to the Free Software
+    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+
+ */
+
+/*
+
+    These files are distributed with VIPS - http://www.vips.ecs.soton.ac.uk
+
+ */
+
+#ifndef IM_INLINE_H
+#define IM_INLINE_H
+
+/* glib promises to define inline in a portable way */
+
+#include <glib.h>
+
+
+#ifdef __cplusplus
+extern "C" {
+#endif /*__cplusplus*/
+
+
+#ifdef HAVE_HYPOT
+
+#define im__hypot hypot
+
+#else /* HAVE_HYPOT */
+
+static inline double im__hypot( double a, double b ){
+  double ta= fabs( a );
+  double tb= fabs( b );
+
+  if( ta > tb ){
+    tb= b / a;
+    return ta * sqrt( 1.0 + tb * tb );
+  }
+  else {
+    ta= a / b;
+    return tb * sqrt( 1.0 + ta * ta );
+  }
+}
+
+#endif /* HAVE_HYPOT */
+
+
+#ifdef __cplusplus
+}
+#endif /*__cplusplus*/
+
+#endif /*IM_INLINE_H*/