diff --git a/src/mesa/main/extensions.c b/src/mesa/main/extensions.c
index b02a49de46e..b7b1e448046 100644
--- a/src/mesa/main/extensions.c
+++ b/src/mesa/main/extensions.c
@@ -747,6 +747,8 @@ get_extension_override( struct gl_context *ctx )
       }
    }
 
+   free(env);
+
    /* Remove trailing space. */
    len = strlen(extra_exts);
    if (extra_exts[len - 1] == ' ')