Fix autotools build.

Follows commits 4e002d9a92ecd7cec0fb98b0bedbace8aad81f6e &
7a90710e0d3c786cf4f3af2457a815db6c9b5a5a that only handled CMake.
Missed two tests!

(Mentioned in #58, thanks!)
Merge pull request #54 from NiLuJe/fix-autotools-build

Fix autotools build.