diff --git a/include/armadillo_bits/compiler_setup.hpp b/include/armadillo_bits/compiler_setup.hpp
index 1b42e892..dbe77a91 100644
--- a/include/armadillo_bits/compiler_setup.hpp
+++ b/include/armadillo_bits/compiler_setup.hpp
@@ -27,7 +27,6 @@
 #undef arma_inline
 #undef arma_noinline
 #undef arma_ignore
-#undef arma_if_constexpr
 
 #define arma_hot
 #define arma_cold
@@ -39,7 +38,6 @@
 #define arma_inline            inline
 #define arma_noinline
 #define arma_ignore(variable)  ((void)(variable))
-#define arma_if_constexpr      if
 
 #undef arma_fortran_sans_prefix_B
 #undef arma_fortran_with_prefix_B
@@ -145,12 +143,6 @@
 // #endif
 
 
-#if (defined(ARMA_HAVE_CXX17) && defined(__cpp_if_constexpr))
-  #undef  arma_if_constexpr
-  #define arma_if_constexpr if constexpr
-#endif
-
-
 #if !defined(ARMA_ALLOW_FAKE_GCC)
   #if (defined(__GNUG__) || defined(__GNUC__)) && (defined(__INTEL_COMPILER) || defined(__NVCC__) || defined(__CUDACC__) || defined(__PGI) || defined(__PATHSCALE__) || defined(__ARMCC_VERSION) || defined(__IBMCPP__))
     #undef  ARMA_DETECTED_FAKE_GCC