diff --git a/src/riemann.h b/src/riemann.h
index 0191058e3ba856d7dcec42ba6185def3ee71d090..d0ae57a640e13c2098708735d6c34de70ebea5b0 100644
--- a/src/riemann.h
+++ b/src/riemann.h
@@ -27,6 +27,14 @@
 #include "stdio.h"
 #include "stdlib.h"
 
+/* Check that we use an ideal equation of state, since other equations of state
+   are not compatible with these Riemann solvers. */
+#ifndef EOS_IDEAL_GAS
+#error Currently there are no Riemann solvers that can handle the requested \
+       equation of state. Select an ideal gas equation of state if you want to \
+       use this hydro scheme!
+#endif
+
 #if defined(RIEMANN_SOLVER_EXACT)
 
 #define RIEMANN_SOLVER_IMPLEMENTATION "Exact Riemann solver (Toro 2009)"