diff --git a/var/spack/repos/builtin/packages/omega-h/package.py b/var/spack/repos/builtin/packages/omega-h/package.py
index d2bee167330bad55a0b301e7064d00a15b148434..2300674c921d4c22fad114f19b28f4507e655325 100644
--- a/var/spack/repos/builtin/packages/omega-h/package.py
+++ b/var/spack/repos/builtin/packages/omega-h/package.py
@@ -78,6 +78,8 @@ def cmake_args(self):
             args.append('-DOmega_h_THROW:BOOL=ON')
         else:
             args.append('-DOmega_h_THROW:BOOL=OFF')
+        # omega-h requires empty CMAKE_BUILD_TYPE
+        args.append('-DCMAKE_BUILD_TYPE:STRING=')
         args += list(self._bob_options())
         return args