diff --git a/protocols/vnc/configure.in b/protocols/vnc/configure.in
index 05ffff6c..35d8c3fa 100644
--- a/protocols/vnc/configure.in
+++ b/protocols/vnc/configure.in
@@ -10,9 +10,9 @@ AC_PROG_CC
 AC_PROG_LIBTOOL
 
 # Checks for libraries.
-AC_CHECK_LIB([guac], [guac_get_client])
-AC_CHECK_LIB([png], [png_write_png])
-AC_CHECK_LIB([vncclient], [rfbInitClient])
+AC_CHECK_LIB([guac], [guac_get_client],, AC_MSG_ERROR("libguac is required for communication via the guacamole protocol"))
+AC_CHECK_LIB([png], [png_write_png],, AC_MSG_ERROR("libpng is required for writing png messages"))
+AC_CHECK_LIB([vncclient], [rfbInitClient],, AC_MSG_ERROR("libvncclient is required"))
 
 # Checks for header files.
 AC_CHECK_HEADERS([stdlib.h string.h syslog.h guacamole/client.h guacamole/guacio.h guacamole/protocol.h])