diff --git a/configure b/configure
index 0b53facfb28bd4a9d52d236ea9122c47b04110c7..8e25a2456c1b9e54353e650e0601bf3556b2afab 100755
--- a/configure
+++ b/configure
@@ -2434,9 +2434,11 @@ if test $sdlabi = "2.0"; then
     sdl_config=$sdl2_config
     sdlname=sdl2
     sdlconfigname=sdl2_config
-else
+elif test $sdlabi = "1.2"; then
     sdlname=sdl
     sdlconfigname=sdl_config
+else
+    error_exit "Unknown sdlabi $sdlabi, must be 1.2 or 2.0"
 fi
 
 if test "`basename $sdl_config`" != $sdlconfigname && ! has ${sdl_config}; then