diff --git a/docs/manual/prerequisite.txt b/docs/manual/prerequisite.txt
index 7edad1f6db..ac0ab62e35 100644
--- a/docs/manual/prerequisite.txt
+++ b/docs/manual/prerequisite.txt
@@ -35,6 +35,7 @@ between distributions).
 ** +python+ (version 2.6 or any later)
 ** +unzip+
 ** +rsync+
+** +file+ (must be in +/usr/bin/file+)
 
 * Source fetching tools:
 ** +wget+
diff --git a/support/dependencies/dependencies.sh b/support/dependencies/dependencies.sh
index bfd65960ce..168d1960a1 100755
--- a/support/dependencies/dependencies.sh
+++ b/support/dependencies/dependencies.sh
@@ -69,6 +69,10 @@ check_prog_host "which"
 # Verify that sed is installed
 check_prog_host "sed"
 
+# 'file' must be present and must be exactly /usr/bin/file,
+# otherwise libtool fails in incomprehensible ways.
+check_prog_host "/usr/bin/file"
+
 # Check make
 MAKE=$(which make 2> /dev/null)
 if [ -z "$MAKE" ] ; then