diff --git a/test-tool/libguestfs-test-tool.pod b/test-tool/libguestfs-test-tool.pod
index 5957c88ea..c96acb7fd 100644
--- a/test-tool/libguestfs-test-tool.pod
+++ b/test-tool/libguestfs-test-tool.pod
@@ -56,9 +56,8 @@ directory to try it.
 
 =item B<--timeout N>
 
-Set the launch timeout to C<N> seconds.  The default is 120 seconds
-which does not usually need to be adjusted unless your machine is very
-slow.
+Set the launch timeout to C<N> seconds.  The default is 600 seconds
+(10 minutes) which does not usually need to be adjusted.
 
 =back
 
diff --git a/test-tool/test-tool.c b/test-tool/test-tool.c
index 59b9d67a8..ca8d9b8c4 100644
--- a/test-tool/test-tool.c
+++ b/test-tool/test-tool.c
@@ -64,7 +64,7 @@
 #define P_tmpdir "/tmp"
 #endif
 
-#define DEFAULT_TIMEOUT 120
+#define DEFAULT_TIMEOUT 600
 
 static int timeout = DEFAULT_TIMEOUT;
 static char tmpf[] = P_tmpdir "/libguestfs-test-tool-sda-XXXXXX";