--- autopano-sift-C-2.5.1/CMakeLists.txt.orig	2010-11-14 15:49:18.744042505 +0100
+++ autopano-sift-C-2.5.1/CMakeLists.txt	2010-11-14 15:51:13.454030665 +0100
@@ -122,7 +122,7 @@ SET(LIBSIFT_SOURCES LoweDetector.c RANSA
 ADD_LIBRARY(libsift STATIC ${LIBSIFT_SOURCES})
 
 set(all_libs libsift ${JPEG_LIBRARIES} ${TIFF_LIBRARIES}
-    ${PNG_LIBRARIES} ${ZLIB_LIBRARIES} ${PANO13_LIBRARIES} ${LIBXML2_LIBRARIES}) 
+    ${PNG_LIBRARIES} ${ZLIB_LIBRARIES} ${PANO13_LIBRARIES} ${LIBXML2_LIBRARIES} -lm) 
 
 add_executable(generatekeys GenerateKeys.c)
 TARGET_LINK_LIBRARIES(generatekeys ${all_libs})