--- a/Imake.cf
+++ b/Imake.cf
@@ -1037,6 +1037,17 @@
 #   define AArch64Architecture
 #   undef __aarch64__
 # endif
+# if defined(__riscv)
+#   undef __riscv
+#   if __riscv_xlen == 64
+#     undef __riscv_xlen
+#     define RV64Architecture
+#   endif
+#   if __riscv_xlen == 32
+#     undef __riscv_xlen
+#     define RV32Architecture
+#   endif
+# endif
 #endif /* linux || __GLIBC__ */
 
 #if (defined(__Lynx__) || defined(Lynx)) && (defined(i386) || defined(__i386__) || defined(__x86__) || defined(__powerpc__) || defined(__sparc__) || defined(sparc))
--- a/linux.cf
+++ b/linux.cf
@@ -584,7 +584,7 @@
 #define MkdirHierCmd		mkdir -p
 
 #ifndef HaveLib64
-# if defined (AMD64Architecture) || defined (s390xArchitecture) || defined (Ppc64Architecture) || defined (AArch64Architecture)
+# if defined (AMD64Architecture) || defined (s390xArchitecture) || defined (Ppc64Architecture) || defined (AArch64Architecture) || defined (RV64Architecture)
 #  define HaveLib64	YES
 # else
 #  define HaveLib64	NO
@@ -1000,6 +1000,24 @@
 # define ServerExtraDefines    -DGCCUSESGAS XFree86ServerDefines -D_XSERVER64
 #endif /* AArch64Architecture */
 
+#ifdef RV64Architecture
+# ifndef OptimizedCDebugFlags
+#  define OptimizedCDebugFlags -O2 GccAliasingArgs
+# endif
+# define LinuxMachineDefines	-D__riscv -D__riscv_xlen=64
+# define ServerOSDefines	XFree86ServerOSDefines -DDDXTIME
+# define ServerExtraDefines	-DGCCUSESGAS XFree86ServerDefines -D_XSERVER64
+#endif /* RV64Architecture */
+
+#ifdef RV32Architecture
+# ifndef OptimizedCDebugFlags
+#  define OptimizedCDebugFlags -O2 GccAliasingArgs
+# endif
+# define LinuxMachineDefines	-D__riscv -D__riscv_xlen=32
+# define ServerOSDefines	XFree86ServerOSDefines -DDDXTIME
+# define ServerExtraDefines	-DGCCUSESGAS XFree86ServerDefines
+#endif /* RV32Architecture */
+
 #ifndef StandardDefines
 # ifdef __linux__
 #  define StandardDefines	-Dlinux LinuxMachineDefines LinuxSourceDefines