The so-called compatibility problem for relativistic wave equations in Riemann spaces \(V_ 4\) has its counterpart in Riemann-Cartan spaces \(U_ 4\). What is to be understood by incompatibility is elucidated. It is shown that in a \(U_ 4\), the minimally coupled massive spin-S Dirac equations imply constraints for all values of \(S>\). In a \(U_ 4\) (though not in a \(V_ 4)\), one has a constraint already when \(S=1\). It is shown that the equations can be compatible (when \(S\geq 1)\) only if torsion is absent, i.e., if the \(U_ 4\) is in fact a \(V_ 4\). If one contemplates the equations on the level of first quantization, the minimal coupling prescription is inappropriate, and minimal Hermitian coupling is prescribed in its place. However, the previous conclusion, that for \(S\geq 1\) the equations are always incompatible in the presence of torsion, remains valid.