https://bugs.gentoo.org/516274
diff --git a/cc_help.sh.in b/cc_help.sh.in
index b20feb6..1820304 100644
--- a/cc_help.sh.in
+++ b/cc_help.sh.in
@@ -7,2 +7,3 @@ LIBS_PNG='@LIBS_PNG@'
 LIBS_TIFF='@LIBS_TIFF@'
+LIBS_MATH='@LIBS_MATH@'
 ENABLE_DEBUG='@ENABLE_DEBUG@'
diff --git a/configure.in b/configure.in
index d11f42c..459ad8f 100644
--- a/configure.in
+++ b/configure.in
@@ -125,2 +125,8 @@ fi
 
+LIBS=""
+AC_SEARCH_LIBS([pow], [m], [LIBS_MATH="$LIBS"], [
+  AC_MSG_ERROR([unable to find the pow() function])
+])
+AC_SUBST(LIBS_MATH)
+
 dnl Checks for header files.
diff --git a/do.sh b/do.sh
index fa15db8..0e9f449 100755
--- a/do.sh
+++ b/do.sh
@@ -117,3 +117,3 @@ SOURCES='png22pnm.c'
 TARGET=png22pnm
-LIBS="$LIBS_PNG"
+LIBS="$LIBS_PNG $LIBS_MATH"
 build