diff --git a/arch/risc-v/src/cmake/Toolchain.cmake b/arch/risc-v/src/cmake/Toolchain.cmake
index b155953a05..e3c82031fb 100644
--- a/arch/risc-v/src/cmake/Toolchain.cmake
+++ b/arch/risc-v/src/cmake/Toolchain.cmake
@@ -343,21 +343,19 @@ if(CONFIG_RISCV_TOOLCHAIN STREQUAL GNU_RVG)
   # These models can't cover all implementation of RISCV, but it's enough for
   # most cases.
 
-  set(LLVM_CPUFLAGS)
-
   if(CONFIG_ARCH_RV32)
-    if(${ARCHCPUEXTFLAGS} STREQUAL imc)
-      list(APPEND LLVM_CPUFLAGS -mcpu=sifive-e20)
-    elseif(${ARCHCPUEXTFLAGS} STREQUAL imac)
-      list(APPEND LLVM_CPUFLAGS -mcpu=sifive-e31)
-    elseif(${ARCHCPUEXTFLAGS} STREQUAL imafc)
-      list(APPEND LLVM_CPUFLAGS -mcpu=sifive-e76)
+    if(${ARCHCPUEXTFLAGS} MATCHES "^imc")
+      set(LLVM_CPUTYPE "sifive-e20")
+    elseif(${ARCHCPUEXTFLAGS} MATCHES "^imac")
+      set(LLVM_CPUTYPE "sifive-e31")
+    elseif(${ARCHCPUEXTFLAGS} MATCHES "^imafc")
+      set(LLVM_CPUTYPE "sifive-e76")
     endif()
   else()
-    if(${ARCHCPUEXTFLAGS} STREQUAL imac)
-      list(APPEND LLVM_CPUFLAGS -mcpu=sifive-s51)
-    elseif(${ARCHCPUEXTFLAGS} STREQUAL imafdc)
-      list(APPEND LLVM_CPUFLAGS -mcpu=sifive-u54)
+    if(${ARCHCPUEXTFLAGS} MATCHES "^imac")
+      set(LLVM_CPUTYPE "sifive-s51")
+    elseif(${ARCHCPUEXTFLAGS} MATCHES "^imafdc")
+      set(LLVM_CPUTYPE "sifive-u54")
     endif()
   endif()